• Korean Chemical Engineering Research
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• v.47 no.6
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• pp.734-739
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• 2009

Characteristics of pyrolysis, partial oxidation, combustion of chlorella, which is one species of micro-algae, were determined by using thermobalance reactor(I.D. 5.5 cm, Height 1 m). Effect of reaction temperature($500{\sim}800^{\circ}C$), water content in chlorella(0~60%), and oxygen content(0~21vol%) on thermal decomposition of chlorella were also determined and analyzed to investigate the kinetic characteristics of pyrolysis, partial oxidation and combustion. As the temperature and partial pressure increases, the carbon conversion increases. In case of pyrolysis, carbon conversion and reactivity sharply decreased with increasing moisture content. However, carbon conversion and reactivity decreased at 60% water content in case of partial oxidation and combustion. As reaction temperature and oxygen content increased, carbon conversion increased and the combustion reaction rate equation for chlorella has been presented. $\frac{dX}{dt}=(7.41{\times}10^{-1})$exp$\left(-\frac{19600}{RT}\right)(P_{O_{2}})^{0.209}(1-X)^{2/3}$.

• Journal of the Korean Society of Combustion
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• v.7 no.3
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• pp.16-22
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• 2002

Combustion performance of an internally cycloned circulating fluidized bed for paper sludge was discussed through a series of batch type experiments. Operation parameters such as water content, feeding mass of sludge and secondary air injection rate were varied to find out the effect on the combustion performance, which was examined with carbon conversion rate and pollutant emission such as CO and NOx. A conventional solid fuel reaction was observed in the experiments of varying water content and feeding mass of the sludge, which is characterized with kinetic limited reaction zone, diffusion limited reaction zone and transition zone. Secondary air injection with swirl enhances the mixing of the gas phase as well as the solid phase, and improves combustion efficiency accompanied with higher carbon conversion rate and lower pollutant emission rate.

• Carbon letters
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• v.1 no.1
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• pp.17-21
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• 2000

Catalytic reduction and oxidation of NO over polyacrylonitrile based activated carbon fibers (PAN-ACF) under various conditions were carried out to develop removal process of NO from the flue gas. The effect of temperature, oxygen concentration and the moisture content for the reduction of NO with ammonia as a reducing agent was investigated. The reduction of NO increased with the oxygen concentration, but decreased with the increased temperature. The moisture content in the flue gas affects the reduction of NO as the inhibition of the adsorption of the other components and the reaction on the surface of ACE For the oxidation of NO to $NO_2$ over PAN-ACF without using a reducing gas, it showed the temperature and the oxygen concentration of the flue gas are the important factors for the NO conversion in which the conversion increased with oxygen concentration and decreased with the temperature increase and might be the alternative option for the selective catalytic reduction process.

• Korean Chemical Engineering Research
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• v.56 no.5
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• pp.738-751
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• 2018

The effect of the reaction temperature and reaction time on the thermal oxidative purification quality of detonation nanodiamond (NDsoot) was investigated in a gas-solid fluidized bed reactor of a $0.10m-ID{\times}1.0m$-high stainless steel column with zirconia beads ($d_{SV}=99.2{\mu}m$). The carbon conversion increased with increasing the reaction temperature; however, when the reaction temperature was greater than 773 K, the carbon conversion did not increase. The content of $sp^3$-hybridized carbon at the reaction temperature of 703 K barely changed when the reaction time was more than 30 minutes, but at 773 K, the content decreased as preferred. At 703 K, the purification quality increased with the increasing reaction time; however, at 773 K, the purification quality increased up to 30 minutes and then decreased rapidly.

• Journal of the Korean Ceramic Society
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• v.27 no.6
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• pp.817-823
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• 1990

Pilot-scale experiments on the oxidation of TiCl4 to produce TiO2 were carried out in a verical reactor of 20cm in inside diameter and 140cm in length ; LPG burning was used as a heating means to maintain the reaciton temperature. The effects of reaction temperature and excess oxygen content on the conversion of TiCl4 and on the particle size of produced TiO2 were investigated. The ranges of operating conditions varied were 900 to TiO2 was 0.45-0.57${\mu}{\textrm}{m}$, TiCl4 conversion was 82-96%, the rutile content was 33-57% and the contents of impurities were 0.03% of Fe, 0.03% of SiO2 and 62ppm of Cl. These experimental results were compared with those of other investigators.

• Korean Chemical Engineering Research
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• v.44 no.6
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• pp.631-635
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• 2006

To investigate the characteristics of substitute natural gas (SNG) production from direct coal methanation, the continuous lab-scale entrained flow hydrogasifier (I.D. : 0.025 m, Height : 1.0 m) was used in this experiment. The hydrogasification system consisted of high pressure gas handling system, high pressure coal feeder, entrained flow hydrogasifier, and unreacted char separator. The experiment was performed at the various conditions of reaction temperature ($600{\sim}800^{\circ}C$), $H_2$/coal ratio (0.2~0.4), and coal feed rate (0.8~2.5 g/min). Although it was shown that carbon conversion was different trends with coals from the methanation results for 6 sample coals, the carbon conversion increased with increasing reaction temperature. And it increased with increasing H2/coal ratio, whereas the concentration of CH4 decreased. Also. the carbon conversion increased with the carbon content of coal sample and had a maximum value at volatile matter content of 35 wt％.

• Journal of the Korean housing association
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• v.21 no.1
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• pp.123-130
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• 2010

The purpose of this study is to find the characteristics of space utilization and the problems that follows after converting in a new developmental residential area. This study used the content-analysis method and analysis was made on the floor plans for 95 different conversion cases. Above all, 190 unit plans (the unit plans for conversion before and after) were analyzed. The results of this study were as follows; 1) There were 8 types of conversion according to such usages as residential, commercial and residential-commercial buildings. 2) In the case of conversions, from residential to commercial, there was a tendency each floor was integrated to exclusive use for commercial or commercial with small portions of residential usage. And in the case of conversions from commercial to residential, there was a tendency that all space of each floor were changed to exclusive usages for residential purposes. 3) In case of usage conversion from commercial to residential, there were constraints for balcony installation, because of its original lot-structure and building equipments. Also, when the basement was converted for residential purpose, there was no possibility for an extra lighting or ways to ventilate the area.

• Korean Journal of Food Science and Technology
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• v.32 no.5
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• pp.1043-1050
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• 2000

The nutritional value of commercial instant noodles produced in summer and winter seasons were investigated. Only the noodle itself was used for the analysis. The content of carbohydrate was calculated by difference. The calorie was estimated by using a conversion factor of 4.32 for protein, 9.21 for fat and 4.20 for carbohydrate. Bag-type instant noodles had higher moisture, but lower content of fat and calorie compared with bowl-type products. No seasonal variations on composition and calorie were found. The calorie was negatively correlated with moisture or carbohydrate content, and positively correlated with fat content. The calorie estimated from linear regression equation of calorie vs. moisture was similar to the value calculated using a conversion factor, which implies that the calorie of the instant noodle can be simply estimated from the moisture content. The intakes of calorie from fat accounted for 30.8% and 34.1% from bag-type and bowl-type noodles, respectively. The content of ash and fat, and calorie were significantly decreased upon cooking, which were more pronounced in the bowl-type products. At the same moisture contents the loss of calorie for bag-type products was 3.5% and for bowl-type ones was 7.7%.

• New & Renewable Energy
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• v.19 no.4
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• pp.27-34
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• 2023

In this study, microalgal oil was extracted from Nannochloropsis oceanica cultured in an open raceway pond and converted into biodiesel using a solid acid catalyst. Microalgal oil was extracted from two types of microalgae with and without nitrogen starvation using the KOH-solvent extraction method and the fatty acid content and oil extraction yield from each microalgae were compared. The fatty acid content of N. oceanica was 184.8 mg/g cell under basic conditions, and the oil content increased to 340.1 mg/g under nitrogen starvation conditions. Oil extraction yields were 90.8 and 95.4% in the first extraction, and increased to 97.5 and 98.8% after the second extraction. Microalgal oil extracted by KOH-solvent extraction was yellow in color and had reduced viscosity due to chlorophyll removal. In biodiesel conversion using the catalyst SO₄^2-/HZSM-5, solvent-extracted oil showed a FAME content of 4.8%, while KOH-solvent-extracted oil showed a FAME content of 90.4%. Solid acid catalyst application has been made easier by removal of chlorophyll from microalgal oil. The FAME content increased to 96.6% upon distillation, and the oxidation stability increased to 11.07 h with addition of rapeseed biodiesel and 1,000 ppm butylated hydroxyanisole.

• Resources Recycling
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• v.15 no.1 s.69
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• pp.66-73
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• 2006

The effects of operation conditions, such as bed temperature, temperature rising rate, particle size, moisture content and so on, on thermo-chemical conversion of waste wood have been determined in a micro fixed bed gasifier. The samples were waste wood-chips such as pine, oak, acacia and ginkgo. The thinning timbers used as reactants in the experiments had $35wt\%$ moisture content, $0.5wt\%$ ash content and 4,550 kcal/kg heating value on a dry basis. A typical product distribution was a $40wt\%$ liquid, $20wt\%$ solid, and $40wt\%$ dry syngas. The syngas concentration was affected by operation conditions and average syngas concentration was $H_2:40vol\%,\;CO:30vol\%,\;CH_4:10vol\%$.