• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2005.05a
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• pp.196-202
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• 2005

• Resources Recycling
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• v.30 no.1
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• pp.60-65
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• 2021

The recycling of titanium turning scraps requires the removal of cutting oil and other contaminants remaining on the surface. In this study, an experiment was conducted in which titanium scraps were cleaned by a combination of ultrasonic immersion-steam cleaning and subsequent drying at high temperature. To determine the removal mechanism of cutting oil, the contact angle between titanium surface and cutting oil was measured. The result confirmed the optimum condition of the immersion solution of the titanium turning scraps. In the case of immersion cleaning of Na4P2O7 aqueous solution, the degree of carbon removed in the cutting oil was the highest at 50℃, and it was confirmed that the carbon content obtained from the combination of steam cleaning and ultrasonic immersion-steam cleaning was lower than that from steam cleaning after ultrasonic immersion. The oxidation and decomposition behaviors of cutting oil were investigated using Thermogravimetric analysis (TGA) and the result was applied in the high temperature drying process. From the results of the high temperature drying tests, it was concluded that 200℃ is the optimal drying temperature.

• 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.17 no.4
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• pp.29-35
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• 2009

Pyrolysis is recently used as one of alternative methods of animal waste treatment. In this study bio-oil was produced at $550^{\circ}C$ in an auger reactor through pyrolysis process. Two pig waste mixtures were used, pig feces mixed with rice husks and pig feces mixed with sawdust. The main compositions of hemicellulose, lignin, cellulose, protein, and fat were analyzed chemically. Based on the main composition results obtained, the contents of holocellulose (the sum of hemicellulose and cellulose) and lignin had a significant positive effect on bio-oil production, and there was a significant negative effect of ash content on bio-oil yield. The interactions between the different feedstocks were evaluated, and it was concluded that the interaction between pig feces and rice husks was minimal, whereas the interaction between pig feces and sawdust was significant.

• Journal of the Korea Organic Resources Recycling Association
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• v.16 no.4
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• pp.50-56
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• 2008

Aqueous thermal liquefaction of rice, barley, wheat, and rapeseed straws was investigated to compare the amount of heavy oil with catalysts such as $K_2CO_3$, NaOH and KOH in the reaction temperature at $320^{\circ}C$ for 10 minutes. The reaction was carried out in a 5,000ml liquefaction system with dispenser and external electrical furnace. Raw materials (160g), 2,000ml of distilled water and 10% (wt/wt) of catalyst to plant residue were fed into the reactor. It was observed that the maximum heavy oil yield was about 29% from the feeding stock, barley straw, with addition of KOH. The caloric values of crude oil from different crop residues were ranged from 55% to 66% relative to the raw materials depend on crop residue. It was appeared that its maximum calorific value from wheat straw was approximately 6190 kcal/kg.

• Journal of the Korea Organic Resources Recycling Association
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• v.32 no.2
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• pp.27-35
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• 2024

It was known that crude oil can be mainly divided into saturates, aromatics, resins, and asphaltenes. If microbial biodegradation of asphaltenes is effectively viable, additional oil production will be expected from depleted oil reservoir. Meanwhile, biodegradation can be applied to other aspects, such as the bioremediation of spilled oil. In this case, the biodegradation of asphaltenes also plays an important role. It has been already reported that asphaltenes are decomposed by bacterial consortia. However, the biodegradation mechanism of asphaltenes has not been clearly presented. The major reason is that the molecular structure of asphaltenes is complicated and is mainly in a aggregated form. In this paper, it was presumed that the biodegradation process of asphaltenes may follow the microbial oxidation mechanism of saturates and aromatics which are easier biodegradable than asphaltenes among the crude oil components. In other words, the biodegradation process was explained by serial stages; the contact between asphaltenes and bacteria in the presence of biosurfactants, and the decomposition of alkyl groups and fused-rings within the asphaltene structure.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.111-116
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• 2001

Waste office paper, photocopied or laser printed, has recently increased along with office automatization. In waste office paper, toner ink is used as the printing medium in place of conventional oil ink. Since toner ink cannot be saponificated by alkali and be decolored by bleaching, different from the case of oil ink, toner remains on regenerated paper as black specks. Although cascade recycling of waste office paper is compelled at present, the demand for low-grade paper is limited. From such circumstances, a new separation process for waste office paper is demanded to achieve parallel recycling. At the first stage of separation studies, the sharpness of separation is evaluated using small separators to obtain fundamental data. In a lab-scale separator, the sample amount of one feed is generally a few grams. However, the sample amount used for brightness, ERIC, and image analysis that are generally used to evaluate the efficiency of deinking are not small for lab-scale tests of these analyses. This paper describes an investigation of a sheet preparation method by a small amount of sample under 0.5g and compares the precision of toner content determination of spectroscopic analysis and image analysis from the viewpoint of separation evaluation. The easiness and convenience of the operation using only general-purpose equipments has also been set as a principle purpose. From the viewpoint of an analysis that yields high precision with a small amount of sample in short time, the method calculating the absorption coefficient from diffuse reflectance in the visible region is the most rational method in this study.

• Tribology and Lubricants
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• v.22 no.4
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• pp.218-224
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• 2006

The sludge oils were produced necessarily in the ships operation, so that it will be the best way to manage the sludge oils inside ship itself from a viewpoint of the prevention of marine oil pollution. The ultra-sonic breaking system which recycle the sludge oil from ship into usable oil to be brunt is recognized as a most possible recycling device. In this regards, the purpose of this study is to examine erosion damage,on the SS400 specimen by cavitation and the effect of impact pressure generated from the demolition of the cavity of ultrasonic vibration in the marine sludge oil environment.. The erosion damage of specimen was investigated mainly on weight loss, weight loss rate and maximum erosion rate with variation of the oil temperature as well as the change of space between transducer hem and specimen. The experimental results showed that as the space between ultrasonic vibrator horn and specimen disk increased, the weight loss and weight loss rate decreased and the values were larger in SFO than in SLO. The experimental results can be useful to the development of sludge oil disposing systems and to consider a countermeasure for the prevention of erosion damages by cavitation.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.4
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• pp.82-88
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• 2012

The usage of recycling agent is the most effective way of enhancing the performance of recycled asphalt pavement. Generally, many countries accepted these recycling agents retarding the various types of cracks resulted in binder aging. Contrary to such general tendency, recycling agents are used as very small amount in domestic recycling plant. The main reason of this is relatively high price of recycling agent. Even though agent price is high, agent can be a effective and economical way of alternative in asphalt recycling. In this study, penetration and softning point test performed by using RTFO(Rolling Thin Film Oven) aged binder. And, PG(Performance Grade) at high temperature, fatigue and MSCR(Multi Stress Creep and Recovery) tests exercised. The oil type agent is worked well to retrieving target penetration number. In PG test, $G^*/sin{\delta}$ of agents identically showed high value and polymer type agent is good at recovery value.

• Journal of the Korea Organic Resources Recycling Association
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• v.18 no.1
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• pp.110-118
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• 2010

Supercritical treatment of liquefaction technology for rice hull was investigated the biomass conversion rate and evaluated its crude oil in respect to feasibility of burner in order to heat the green house. The reaction was carried out in a 5,000 mL liquefaction system with dispenser and external electrical furnace. Raw materials (160 g) of rice hull and 3,000 mL of different solvents were fed into the reactor. It was observed that the maximum crude oil yield was about 84.4 % with 1-butanol. The calorific value of crude oil from ethanol solvent were 7,752 kcal/kg. Furthermore, in case study of co-solvent with ethanol and bulk-glycerol, it observed that more than 80 % of rice hull was decomposed and liquefied in its solvent at $315{\sim}326^{\circ}C$ for 30 min. For the development of applicable bio-fuel from rice hull, it was considered that its feasibility is necessary to be carried out for co-solvent soluble portions. Regarding to utilize the crude oil into burner as fuel, it was observed that its calorific value was lower at approximately 24 % than the diesel. Also, flame length from crude oil at lower temperature was decreasing due to incomplete incineration. The temperature of warm wind on the burner was maintained between 63 and $65^{\circ}C$, and the temperature of emission line was appeared at $350{\sim}380^{\circ}C$.