• Resources Recycling
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• v.15 no.1 s.69
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• pp.3-11
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• 2006

Fast pyrolysis of Quercus acutissima was carried out in a fluidized bed pyrolyser and then the physicochemical properities of obtained bio-oil were analyzed using GC/MS. The yields of bio-oil of Quercus acutissima and Larix leptolepis from a fluidized bed pyrolyzer were maximized at $350^{\circ}C\;and\;400^{\circ}C$, respectively. This is due to the difference or cellulose content between the two tree species. Above the optimum temperature, the yields of char and oil decreased as the reaction temperature increased, but the yield of gas-phase and water fraction increased. It is concluded that this phenomenon is occured by secondary pyrolysis in the free board. The feeding rate of the sample in a fluidized bed pyrolyser did not affect the yields and composition of products, because of a sufficient mixing between bed materials and sand.

• Journal of the Korea Organic Resources Recycling Association
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• v.20 no.3
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• pp.83-88
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• 2012

The algal bloom, resulting from eutrophication, has caused serious water quality problems in river and lake. Therefore, it has to be removed by any means including physicochemical or biological treatment for preserving water quality. This study was conducted to investigate the microalgae removal and energy production using combined electro-flotation and anaerobic hydrogen fermentation processes. The result showed that algae removal efficiency based on chlorophyll a removal increased with the current. At a current of 0.6A, the maximum microalgae removal efficiency of 95.9% was achieved. The treatability of anaerobic hydrogen fermentation was investigated to recover energy from microalgae removed by electro-flotation. The ultimate hydrogen yields of algae before and after ultrasonic pretreatment were 17.3 and 61.1 ml $H_2/g$ dcw(dry cell weight), respectively. The ultrasonic pretreatment of algae led to 3.4-fold higher $H_2$ production due to the increase of hydrolysis rate.

• Journal of the Korea Organic Resources Recycling Association
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• v.21 no.1
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• pp.76-84
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• 2013

In this study, thermal weight loss, non-isothermally experiment, chemical composition analysis, calorific value, activation energy (E) were investigated to analysis the kinetic study of RDF, wood pellets, waste wood, waste textile and waste vinyl. When the chemical composition of solidification fuel was compared, the moisture content of RDF was less than the wood pellet and when the kinetic study was compared, the combustion reaction rate of the waste vinyl was higher than any other solidification fuels. However when the combustion efficiency was compared by the activation energy, the RDF had the higher efficiency than other wastes. RDF can be found that the reaction takes place between $320{\sim}720^{\circ}C$ depending on the heating rate.

• Journal of the Korea Organic Resources Recycling Association
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• v.21 no.3
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• pp.82-92
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• 2013

The Intermittent Aeration MBR systems have the advantage of controlling reaction time by changing aeration period and are one of economic BNR systems since these processes do not require MLSS recirculation that demands capital and operation costs. In this study, two intermittent aeration MBR systems were studied by computer simulation: an intermittent aeration MBR system that had both 1hr/1hr and 4hr/4hr aeration/unaeration periods at intermittent reactor and NEW INTERMITTENT-process that was an energy saving process and certified as a new process by Korean government. Since DO concentration reached only at 0.23mg/L at intermittent reactor when it was aerated, the Intermittent aeration MBR system having 1hr/1hr aeration/unaeration period showed simultaneous nitrification/denitrification and had the highest nitrogen and phosphorus removal efficiencies that were 57% and 55%, respectively. Since this study was based on the constant influent flow and characteristics, more studies are needed to define the operational characteristics of intermittent aeration MBR systems under dynamic influent conditions.

• Journal of the Korea Organic Resources Recycling Association
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• v.21 no.3
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• pp.93-98
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• 2013

Main causes of algal bloom was studied in Paldang reservoir. Statistical approach was tried using meteorological and water quality data. Algae alert system showed that more than ten days were counted in a year, once it happened in Paldang reservoir. Alert dates increased in recent 5 years. Correlation coefficients between chlorophyll-a and other indexes did not showed strong relations resulting in coefficients less than 0.4. Among them, sunshine duration, BOD, and flow rate were appeared relatively main causes of algal blooming. Sunshine duration and BOD showed positive relation while flow rate did negative one, which is resonable for photosynthetic microorganisms. Water temperature and total phosphorus, which were presumed probable main causes before study, resulted in low correlation coefficients. Correlation coefficients between discharge flow and rainfall, water temperature showed positive relation due to seasonal effect.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2005.10a
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• pp.83-96
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• 2005

PVC is the thermoplastic offering excellent material properties. PVC is used in wide variety of applications, however, it causes environmental problems when it is discarded because of its high chlorine content. Since dechlorination reaction of PVC is taking place relatively low temperature compared to the pyrolysis temperature of plastics, study on the dechlorination reaction has been carried out as a pre-treatment process. Twin screw reactor which shows excellent mixing capabilities is employed. Experimental variables are first and second reactor temperature, PVC content in mixed plastics, viscosity of mixed plastics, feeding rate, rotational speed of the second reactor. Over 90% of dechlorination rate can be obtained under proper operation conditions. Chlorine gas evolved from reactor is absorbed in water and can be recovered as a hydrochloric acid. Analysis had been done on chlorine flows by taking material balance over reactor.

• Journal of the Korea Organic Resources Recycling Association
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• v.21 no.4
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• pp.50-61
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• 2013

In order to generate a renewable energy-Methane, anaerobic systems fed with source separated food waste from university cafeteria were studied. At first, four reactors were evaluated with same feed components; content non-mixing anaerobic reactor without leachate withdrawal/recirculation, content mixing anaerobic reactor without leachate withdrawal/recirculation, content non-mixing anaerobic reactor with leachate withdrawal/recirculation and content mixing anaerobic reactor with leachate withdrawal/recirculation. From the first study, content non-mixing anaerobic reactor with leachate withdrawal/recirculation showed the highest gas production. From further study with this system, it was observed that leachate permeation rate within anaerobic reactor was very important factor for gas generation. The higher permeation rate, the more gas production was observed. It is assumed that 1kg of gas collector weight and C/N ration above 10 in food waste may cause gas consumption in the anaerobic reactor. The gas consumption was estimated by negative pressure build-up at gas collector. The negative pressure build-up must be explained to produce Methane from Food Waste.

• Journal of Energy Engineering
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• v.26 no.4
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• pp.14-22
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• 2017

Coffee consumption has been increased all around world as well as in South Korea. Coffee by-products occurred from the coffee consumption also have been rapidly increased, but the technology and methods to handle the by-product have not been much developed, resulting the severe environmental problems in soil and water. In order to solve this environmental problem, using the coffee by-product, eco-friendly and cheap methods for the recycling have been actively discussed and suggested. In this article, we discussed the types and characters of the coffee by-product and investigated the trend about the methods for utilizing the coffee by-product. In addition, we figured out the current status of coffee waste in Seoul, South Korea and discussed plans that Seoul government is working on to handle the coffee waste.

• Resources Recycling
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• v.8 no.4
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• pp.57-63
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• 1999

Wood-Polymer Composites (WPC) m s prepared irom recycled films of agricullural use and wood wastes, and LLDPE and neal PE resin mlxlurr war also utilized in order to cornpiue the praperlies. Molc~ca nhydride (MA) and dicumyl peroxide were used as an adheslon pmmoler and an il~lliatotor~, .espcmivelyT. ensile prapenies of W Cw zrc measured via lenslle test as a funclieu of woad lille~m d MA contmt, and rractu1.e surface was also mvestigaled wilh SEM. As the content of wwd tiller mcreased, clongauon deneased bul modulus increased However, tensile slrength OI WPC increased only when MA war used, and 1 wt.% of MA may be hgh enough to increase the tensile properties. The tensilc ptopcrlies af WPC prepwed from recycled PE films were &nost same as thosc of neal PE resin mixture.

• Resources Recycling
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• v.16 no.5
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• pp.25-30
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• 2007

In Korea, reutilization of construction waste is gaining attention as construction waste generated increases continuously. Currently, the concrete waste is simply crushed and used as a low value application such as paving, back filling, etc. To meet the demand of aggregate for construction and the resource efficiently, production of high quality recycled aggregate is necessary. Therefore, in this study, a better process for production of high quality recycled aggregate was developed using combination of heat pretreatment and autogenous milling. Test results showed that the recycled aggregate has a density of $2.5\;g/cm^3$ and a water absorption ratio of 3.0%, which meet the specification of the first class of KS F 2573. Currently, a pilot scale autogenous mill is being constructed and tests will be further conducted to develop a commerce-scale process.