• The Journal of Engineering Research
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• v.3 no.1
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• pp.199-205
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• 1998

Cullet Quality Control in auto glass bottle factory is the most important in recent days because of the increasing cost of materials in glass bottle. Since the composition of plate glass cullet is similar, the cullet quality using plate cullet in glass bottle factory is easily controlled. In addition to this, the price of plate glass cullet is so low that the cost reduction can be achieved. If the ratio of plate glass cullet and gush is over 25%, the liquidity of glass water become worse, which is caused by different compositions and viscosity of the components. As a results, Furnace bottom temperature becomes low and glass water becomes inhomogeneous. Thus production efficiency of glass bottle becomes low because of increasing devitrification in Dead Corner part in glass melting furnace. Three experimental methods – (1) increasing melting temperature, (2) using Booster, (3) using bubbler – were performed to increase the furnace bottom temperature and glass water homogeneity. The amounts of plate glass cullet was able to increase up to 90%, 70% and 60% without any devitrification using booster, bubbler and the method of glass melting temperature increase from $1480^{\circ}C$ to $1560^{\circ}C$ respectively. It is not possible to increase the glass melting temperature without the reduction of furnace operation time and the increase of fuel cost. The booster process has disadvantage of much electric energy consumption. Since the bubbler process uses physical convection of melting glass based on compression air, the homogeneity of molten glass is not so good as that of booster process but it can reduce the cost of glass bottle.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.4B
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• pp.253-259
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• 2012

Wastewater-adapted microalgae such as Chlorella vulgaris AG10032, Ankistrodesmus gracilis SAG278-2 and Scenedesmus quadricauda AG10308 are useful biological resources for recovering biofuel and other bio-based materials from wastewater because of their efficient removals of nitrogen and phosphorus from wastewater and their high fatty acid contents in biomass. Although the concentrations of phosphorus typically vary in wastewater environment, very little is known about the effect of phosphorus concentration, especially phosphorus starvation, on microalgal fatty acid synthesis. This is partially due to the lack of methodological establishment for algal fatty acid analysis. In this study, we compared the analysis performances of microalgal fatty acids by two different methods; one is a non-polar GC (gas chromatography) column based method, which is generally used for microbial fatty acids, and the other is a polar WAX-type GC column method, which is typically used for plant fatty acids. And then, we explored the effect of phosphorus concentration levels on fatty acid production in microalgae cultivated from wastewater. As results, the polar WAX-type column method has better ability to separate poly unsaturated fatty acids (PUFA) including $C_{18:3}$ (linolenic acid), and was found to be more applicable in analyzing fatty acids from wastewater-cultivated microalgae than the non-polar column method. The fatty acid characterization by the WAX-type column method revealed little effect of phosphorus starvation on the quantity and composition of fatty acids from wastewater-cultivated microalgae.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.10
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• pp.4679-4688
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• 2011

This study was performed to the municipal waste generation amounts and characteristics for B city in Gangwon province, predicted the methane gas generation rate emitted from landfill, and analyzed the possibility of energy recovery to RDF(Refuse Derived Fuel) using combustible waste. The study results showed that the average bulk density of municipal waste for B city was 144.0 kg/$m^3$, and the average ratios of combustible waste were 36.0 % of paper, 21.6 % of vinyl, and 19.7 % of food waste. respectively. In the experiment for heating value, high and low heating value(moisture) was measured to 3,471 $kca{\ell}$/kg and 2,941 $kca{\ell}$/kg, respectively. After the prohibition of burying of food waste in landfill, the heating value of municipal waste was dramatically increased due to increase of the ratio of paper, vinyl, and plastic waste. The prediction results of methane gas generation rate emitted from landfill showed that the gas generation rate is increasing to 2,505.7 CH4 ton/year in 2021. After then, the rate is decreasing gradually. When the RDF facility is installed, the rate is decreasing after peaking at 1,956.9 CH4 ton/year in 2013. The generation rate of LFG emitted from waste landfill of B city was analyzed to 9.92 $m^3$/min, similar to 10.11 $m^3$/min for other city.

• Korean Journal of Materials Research
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• v.9 no.11
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• pp.1075-1082
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• 1999

Composite air electrodes of 50/50 vol% LSM- YSZ where LSM =$\textrm{La}_{1-x}\textrm{Sr}_{x}\textrm{MnO}_{3}$(0$\leq$x$\leq$0.5) were prepared by colloidal deposition technique. The electrodes were then examined by scanning electron microscopy (SEM) and studied by ac impedance spectroscopy in order to improve the performance of a solid oxide fuel cell (SOFC). Reproducible impedance spectra were confirmed by using the improved cell, consisting of LSM- YSZ/YSZ/LSM-YSZ. These spectra were a strong function of operating temperature and the stable conditions for the cells were typically reached at $900^{\circ}C$. The typical spectra measured for an air//air cell at $900^{\circ}C$ were composed of two arcs. Addition of YSZ to the LSM electrode led to a pronounced decrease in cathodic resistivity of LSM-YSZ composite electrodes. Polishing the electrolyte surface to eliminate the influences of surface impurities could further reduce cathode resistivity. The cathodic resistivity of the LSM-YSZ electrodes with catalytic interlayer (Ni or Sr) was much smaller than that of LSM-YSZ electrodes without catalytic interlayer. In addition, the cathodic resistivity of the LSM-YSZ electrodes was a strong function of composition of electrode materials, the electrolyte geometry, and applied current.

• Clean Technology
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• v.18 no.4
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• pp.432-439
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• 2012

The electrocatalytic oxidation of CO was studied using carbon-supported 20 wt% PtRu (PtRu/C) catalysts, which were prepared with different Pt : Ru atomic ratios from 7 : 3 to 3 : 7 using a colloidal method combined with a freeze-drying procedure. The bimetallic PtRu/C catalysts were characterized by various physicochemical analyses, including X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). CO stripping voltammetry measurements indicated that the addition of Ru with a Pt catalyst significantly improved the electrocatalytic activity for CO electrooxidation. Among the tested catalysts, the $Pt_5Ru_5/C$ catalyst had the lowest onset potential (vs.Ag/AgCl) and the largest CO EAS. Structural modification via lattice parameter change and electronic modification in the unfilled d band states for Pt atoms may facilitate the electrooxidation of CO.

• Journal of the Korean Institute of Gas
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• v.19 no.2
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• pp.74-82
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• 2015

Carbon dioxide was designated as one of greenhouse gases that cause global warming. Among various ways to solve the $CO_2$ emission issue, the 3rd-generation biomass (algae) production is considered as a viable method to reduce $CO_2$ in the atmosphere. In this research, we propose a design of an innovative sustainable production system by utilizing the 3rd generation biomass in the environment of floating production storage and offloading (FPSO). Existing biomass production systems depend on the solar energy and they cannot continue producing biomass at night. Electricity produced from offshore wind farms also need an efficient way to store the energy through energy storage system (ESS) or deliver it real-time through power grid, both requiring heavy investment of capital. Thus, we design an offshore grid structure harnessing LED lights to supply the necessary light energy, by using the electricity produced from the wind farm, resulting in the maximized production of biomass and efficient use of wind farm energy. The final design integrates the biomass production system enhanced by LED lights with a wind power generation. The suggested NLP model for the optimal design, implemented in GAMS, would be useful for designing improved offshore biomass production systems combined with the wind farm.

• Korean Chemical Engineering Research
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• v.53 no.6
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• pp.783-791
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• 2015

A fluidized-bed reactor with an inside diameter of 0.1 m and a height of 1.2 m was used to study the effect of steam and catalyst additions to air-blown biomass gasification on the production of producer gas. The equipment consisted of a fluidized bed reactor, a fuel supply system, a cyclone, a condenser, two receivers, steam generator and gas analyzer. Silica sand with a mean particle diameter of $380{\mu}m$ was used as a bed material and calcined dolomite ($356{\mu}m$), which is effective in tar reduction and producer gas purification, was used as the catalyst. Both of Korea wood pellet (KWP) and a pellet form of EFB (empty fruit bunch) which is the byproduct of Southeast Asia palm oil extraction were examined as biomass feeds. In all the experiments, the feeding rates were 50 g/min for EFB and 38 g/min for KWP, respectively at the reaction temperature of $800^{\circ}C$ and an ER (equivalence ratio) of 0.25. The mixing ratio (0~100 wt%) of catalyst was applied to the bed material. Air or an air-steam mixture was used as the injection gas. The SBR (steam to biomass ratio) was 0.3. The composition, tar content, and lower heating value of the generated producer gas were measured. The addition of calcined dolomite decreased tar content in the producer gas with maximum reduction of 67.3 wt%. The addition of calcined dolomite in the air gasification reduced lower heating value of the producer gas. However The addition of calcined dolomite in the air-steam gasification slightly increased its lower heating value.

• 한국석유지질학회:학술대회논문집
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• autumn
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• pp.28-46
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• 2001

Natural gas is a mixture of hydrocarbon gases and impurities such as nitrogen, hydrogen sulfide, and carbon dioxide and a clean energy producing no pollution materials for combustion. Currently, the demand of the natural gas is rapidly increasing due to worldwide environmental problems. According to Hubbert's study in the past, the natural gas was predicted as rapidly depleted resources, and then the results led to high gas price and limitation of usage during 1980s. Afterward, the study of natural gas resources based on geology identified the additional natural gas resources that were not considered in Hubbert's study. They are unconventional gas, additional resources in the existed reservoirs, and natural gas in deep subsurface areas. Such additional resouces made the future of natural gas bright and pormised low and stable gas price in the future. Deep natural gas is defined as the gas existing at or below 15,000ft$(4,752{\cal}m)$ in depth from the surface. According to the study from the U.S. Geological Survey(USGS) in 1995, 1,412 TCF of technically recoverable natural gas was remained to be discovered or developed in the onshore of United States. A significant part of that resource base, 114 TCF, exists at deep sedimentary basins, and it shows wide distribution with various geological environments. In 1995, the deep gas contributed to $6.7\% of total supply amount of natural gas in the United States and is expected to be $18.7\% by 201.5. However, the development of the deep gas is a high risky business due to expensive investment and high portion of dry holes, although it is developed. Thus, for developing the deep gas economically, it is necessary to overcome many technical challenges. In this paper, for increasing success rate of the deep gas, 1) geologic and compositional characteristics, and production cost have been analyzed according to depth, 2) technical problems related to deep gas production have been summarized, and 3) finally future study areas for increasing application of the deep gas have been suggested. For reference, this paper was written based on the study results from USGS and Gas Research Institute(GRI), for the United States is doing the most active R&D in the deep gas area, and thus, has many reliable data.

• Economic and Environmental Geology
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• v.38 no.4 s.173
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• pp.463-479
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• 2005

The Sr and Pb isotopic ratios and chemical composition were measured for atmospheric bulk deposition samples collected in the Jeonju, Gunsan and Namweon areas over a period of one year. Acidity of deposition ranged pH $4\~7$ with little higher in dry season, and around pH 5.0 in rainy season. The EC and TDS of rainy season was low showing dilution effect, and increased during dry season. Sulfate $(SO_4)\;and\;NO_3$ are atmospheric aerosols largely of anthropogenic origin in winter. Sodium was concentrated in winter deposition, Ca was concentrated in spring to summer deposition. Namweon has lower EC and TDS than those of other, and Jeonju has higher. Namweon was concentrated in $HCO_3$ and Cunsan was concentrated in Cl. Aluminium, Cu, and Zn show good correlation index with TDS, indicating of their origin atmospheric. $^{87}Sr/^{86}Sr$ ratios of bulk deposition ranged from 0.7109 to 0.7128. The isotopic variations are correlated with mixing of isotopic compositions of local soils, road deposit and biogenic aerosol. In order to constrain further the origin of aerosols in rainwater, it will be necessary to collect additional Sr isotopic data for aerosols. Lead isotope ratios for all areas were similar and belonged to Pb isotope ratios of Seoul's aerosols, but little different with Beijing's aerosols. It showing that Pb in the Korea mainly derived from the gasoline combustion, not exclusively from the Beijing.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.970-976
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• 2011

Strip tiller equipment was developed to reduce soil erosion in the slope land for highland agricultural area. The equipment consisted of 4 rows strip tillage device and fertilizer applicator. The field was tilled in 10 cm width and in 10 cm depth by the equipment, of which tilled surface was 16.7% of full-width tillage. The working time and fuel consumption of the equipment were $3.8hours\;ha^{-1}$ and $24.4L\;ha^{-1}$ respectively, which were 59% and 74% less than those of the conventional tillage. Fertilizer efficiency of the equipment in cultivation of Chinese cabbage was 1.7, 1.6 and 1.5 times higher in nitrate, phosphorous and potassium respectively, than conventional tillage. When the equipment was used after covering of rye residue, the quantity of runoff was 49~67% lower than the conventional tillage. And the quantity of soil loss were 1.3 and $0.2Mg\;ha^{-1}$ at right after and 30 days after planting of Chinese cabbage respectively, while 11.5 and $4.1Mg\;ha^{-1}$ in conventional tillage. In conclusion, the strip tillage equipment developed in this study can be applicable to slope land, so that soil loss of 90% can be reduced.