• Transactions of the Korean hydrogen and new energy society
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• v.17 no.2
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• pp.141-148
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• 2006

This study was carried out to analyze the microstructure characteristics of electrolyte membrane through XRD, SEM and AC impedance measurement for using in high temperature steam electrolysis(HTE). It was investigated that thermal stability and electric characteristics by sintering condition using dry and wet process, and confirmed growth of particle and density change by sintering temperature. The sintering temperature and behavior had an effect on the relative density of the ceramic and the average grain size. The more amount of dispersant in organic compound increase, the more the density increased. But the binder was shown opposite phenomenon. It was analyzed that electrolyte resistance and electrical characteristics using AC impedance. The electrical properties of YSZ grain boundary changed with the sintering temperature.

• 유체기계공업학회:학술대회논문집
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• 2003.12a
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• pp.278-283
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• 2003

A generation rate of sludge in Korea had increased dramatically about 200 % for a decade. A requirement for high efficiency dewatering system being possible to produce the low water content cake have suggested due to the appearanceof commercial and social problems about handling of dewatered cake. The conventional dewatering system with mechanical compression device was not suitable to produce the low water content cake and didn'tcope with lots of requirements. Therefore, this paper was to develop the high efficient filter press with the compressive and heating forces through the heating plate to be built between membrane filter plates. It is possible to produce the low water content cake and improve the dewatering rate, so this equipment positively coped with several types of problems related to the sludge dewatering. The plate heated by heat transfer materials such as steam, hot water and thermo-oil made the sludge make the residual moisture within the cake to discharge easilyand to improve the dewatering efficiency of equipment. The pilot scale experiment with 500kg of cake production showed that the dewatering efficiency determined by the final water content and dewatering velocity was improved 30% more than the conventional dewatering equipment.

• Journal of the Korean Society of Combustion
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• v.19 no.3
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• pp.34-43
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• 2014

The reformer system is a method for hydrogen production from hydrocarbon fuels such as natural gas under high temperature environment($about{\sim}1,000^{\circ}C$). The premixed swirl burner with mixing swirler and combustion swirler designed to deliver fuel cell electric output from 0.5 kW to 1.5 kW. Premixed swirl burner experiments using natural gas and mixture of natural gas and anode off gas were carried out to analyse flame patterns and stability by equivalence ratio respectively. The results show that the stable swirl flame can be established for all cases of fuels type using the premixed swirl burner. The swirl flame had a wide stability region and it showed very low CO(50 ppm) and $NO_x$(20 ppm) emission at different fuel type and various equivalence ratio conditions. The operating range of premixed swirl burner for stable swirl flame is found to exist between equivalence ratio of 0.70 to 0.90 for turn down ratio of 3:1.

• Microbiology and Biotechnology Letters
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• v.3 no.3
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• pp.135-140
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• 1975

For the purpose of producing single cell protein out of an agricultural waste, chestnut-bur was hydrolyzed with 4％ H$_2$SO$_4$, solution for 30 min under the steam pressure of 1.5kg/$\textrm{cm}^2$, and 21％ saccharification of the original carbon source was obtained. When Candida tropicalis was grown in the hydrolyzate the cell yield remained only 21％ of the original sugar suggesting a necessity of further treatments.

• Microbiology and Biotechnology Letters
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• v.3 no.3
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• pp.141-146
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• 1975

The pre-hydrolyzed residue of Chestnut-bur (1) was treated with 74％ H$_2$SO$_4$, solution at 3$0^{\circ}C$ for 40minutes. Then the solution was diluted to 5％ with distilled water and kept for another 40 minutes under steam pressure of 1.5kg/㎤ to complete the post-hydrolzation. In the resulting hydrolyzate, which showed 49.3％ in saccharification rate, Candida utilis was grown and found that 62.5％ of the reducing sugar had been converted to the yeast cells.

• Advances in concrete construction
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• v.11 no.4
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• pp.307-314
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• 2021

Activated hwangtoh (ACT) is a natural resource abundant in South Korea, approximately 15.0% of soil. It is an efficient mineral admixture that has activated pozzolanic properties through high-temperature heating and rapid cooling. The purpose of this study is to improve a curb mixture that can reduce NOx outside and investigate durability performance. To this end, mortar curb specimens were manufactured by replacing OPC with ACT. The ACT substitution ratios of 0.0, 10.0, and 25.0% were considered, and mechanical and durability tests on the curb specimens were conducted at 28 and 91 days of age. Steam curing was carried out for three days for the production of curbs, which was very effective to strength development at early ages. The reduction in strength at early ages could be compensated through this process, and no significant performance degradation was evaluated in the tests on chloride attack, carbonation, and freezing and thawing. The mortar curb with an ACT of 10.0~25.0% replacement ratio exhibited clear NOx reduction through photocatalytic (TiO2) treatment. This is due to the increase in physical absorption through surface absorption and the photocatalyst-containing TiO2 coating. In this study, the reasonable range of the ACT replacement ratio for NOx reduction was quantitatively evaluated through a comprehensive analysis of each test.

• Korean Chemical Engineering Research
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• v.61 no.2
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• pp.234-239
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• 2023

Waste from the food is a challenge to the environment all over the globe, hence there is need to be recycled. There is a great deal of renewable energy potential in the biomass of vegetables and fruits, which can be used to generate power and steam, as well as fuel for human consumption and laboratory solvents. To maintain the nutritional, antioxidative, and functional qualities of sapota fruit, wine was made by fermenting it with wine yeast (Saccharomyces cerevisiae). The wine's approximate composition was as follows: total soluble solids, 2.38°Brix; total sugar, 3.8 g/100 ml tartaric acidity (TA), 1.29 g tartaric acidity total phenolics, 0.21 g/100 mL; pH, 3.02; acid/100 mL; pH, 3.02; total phenolics, 0.21 g/100 mL; 22 g/100 ml -carotene; 1.78 g/100 ml ascorbic acid mg/100 ml; 0.64 mg/100 ml lactic acid; and The ethanol percentage is 8.23% (v/v). The sapota wine was delicious. A DPPH-scavenging 2, 2-diphenyl-1picryl hydroxyl (DPPH) at a dosage of 250 g/ml, the activity was 46%. Infrared alcohols, phenethylamines, and other compounds were discovered via spectroscopy.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.93-94
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• 2023

Through the industrial revolution that began in the 18th century, the amount of carbon dioxide in the atmosphere increased rapidly as humans used fossil energy such as coal and oil as fuel for steam engines and factory machines. The amount of carbon dioxide emitted while producing cement, the main material of concrete used in construction, is large enough to account for 5-8% of the world's carbon dioxide emissions. In this study, Non cement-based matrix were used to reduce carbon dioxide emissions from cement production. Red mud is an industrial by-product generated in the manufacturing process of aluminum hydroxide using bauxite, and more than 120 million tons are produced worldwide. In addition, red mud is a porous material that can be physically adsorbed, and causes a photocatalytic reaction of TiO₂ to remove harmful substances such as nitrogen oxide formaldehyde in the air and chemically adsorbs ammonia and hydrogen sulfide. Therefore, this study aims to examine the physical properties of the matrix by mixing red mud, an industrial by-product with good adsorption performance, into the Non cement-based matrix.

• Korean Chemical Engineering Research
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• v.45 no.6
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• pp.656-662
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• 2007

Fuel reformer using plasma and shift reactor for CO oxidation were designed and manufactured as $H_2$ supply device to operate a polymer electrolyte membrane fuel cell (PEMFC). $H_2$ selectivity was increased by non-thermal plasma reformer using GlidArc discharge with Ni catalyst simultaneously. Shift reactor was consisted of steam generator, low temperature shifter, high temperature shifter and preferential oxidation reactor. Parametric screening studies of fuel reformer were conducted, in which there were the variations of the catalyst temperature, gas component ratio, total gas ratio and input power. and parametric screening studies of shift reactor were conducted, in which there were the variations of the air flow rate, stema flow rate and temperature. When the $O_2/C$ ratio was 0.64, total gas flow rate was 14.2 l/min, catalytic reactor temperature was $672^{\circ}C$ and input power 1.1 kJ/L, the production of $H_2$ was maximized 41.1%. And $CH_4$ conversion rate, $H_2$ yield and reformer energy density were 88.7%, 54% and 35.2% respectively. When the $O_2/C$ ratio was 0.3 in the PrOx reactor, steam flow ratio was 2.8 in the HTS, and temperature were 475, 314, 260, $235^{\circ}C$ in the HTS, LTS, PrOx, the conversion of CO was optimized conditions of shift reactor using simulated reformate gas. Preheat time of the reactor using plasma was 30 min, component of reformed gas from shift reactor were $H_2$ 38%, CO<10 ppm, $N_2$ 36%, $CO_2$ 21% and $CH_4$ 4%.

• Journal of the Korean Institute of Gas
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• v.23 no.2
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• pp.1-8
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• 2019

Because of environmental pollution problem, interests in hydrogen energy has been concentrating sharply. Especially in Korea, the market related with fuel cell vehicles and hydrogen refueling stations is increasing actively under the government-led. However, the actual contributions to environmental improvement effect of hydrogen energy is required to be evaluated with representing reality. In this sense, lots of conventional analyzing tools have some limitations to adapt in Korea's situation directly. It is caused by the differences of raw energy market between the US and Korea. That is, most of analytic tools are developed by representing energy market of the US, where can produce variety of raw feed energy sources. Therefore, in this paper, we propose mass balance based numerical analyzing method, which is suitable for the actual hydrogen production process in Korea for exact evaluation of $CO_2$ emission amount in this country. Using proposed method, we has demonstrated reformed hydrogen from natural gas, LPG and naphtha, electrolysis-based hydrogen, and COG-based hydrogen. Furthermore, with the comparison of GREET program analysis results, robustness of numerical analysis method is demonstrated.