• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.717-720
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• 2011

Due to the depletion of fossil fuel, high oil price and global warming issue by green house gas such as CO2, clean synthetic fuel technologies using biomass, especially GTL(Gas To Liquid) technology, have been greatly attracted. This paper has examined and compared the worldwide technologies trend of natural gas reforming reaction, F-T(Fisher-Tropsch) synthesis and upgrading process which are three backbones of GTL technology.

• Journal of The Korean Society of Agricultural Engineers
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• v.53 no.6
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• pp.17-22
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• 2011

Biomass gasification provides synthesis gas or syngas that can be used for internal combustion engines as fuel or chemical synthesis as feedstock. Among different types of gasifiers, downdraft gasifier can produce relatively clean syngas with lower tar contents. In this study, a downdraft gasifier was fabricated with 150 mm of hearth diameter to gasify woodchip that is commercially available in this country. After drying woodchip to about 20 %, gasification experiments were conducted measuring temperature, pressure, air and gas flow rates. The volumetric concentrations of CO, $H_2$, $CO_2$, $CH_4$ were 10.7~14.5, 16.5~21.4, 12.5~16.6, and 2.3~2.9, respectively. They were overall within the ranges of the results that the previous studies showed. However, CO concentration was relatively lower and H2 was slightly higher than those from other studies. It seemed that water gas shift reaction was occurred due to the moisture in the fuel woodchip. Additional drying process coupled with syngas cooling would be required to improve the overall efficiency and syngas quality.

• Journal of Hydrogen and New Energy
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• v.17 no.4
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• pp.362-370
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• 2006

The purpose of this paper was to investigate the reforming characteristics and optimum operating condition of the plasmatron assisted $CH_4$ reforming reaction for the hydrogen-rich gas production. Also, in order to increase the hydrogen production and the methane conversion rate, parametric screening studies were conducted, in which there were the variations of the $CH_4$ flow ratio, $CO_2$ flow ratio, vapor flow ratio, mixing flow ratio and catalyst addition in reactor. High temperature plasma flame was generated by air and arc discharge. The air flow rate and input electric power were fixed 5.1 l/min and 6.4 kW, respectively. When the $CH_4$ flow ratio was 38.5%, the production of hydrogen was maximized and optimal methane conversion rate was 99.2%. Under these optimal conditions, the following synthesis gas concentrations were determined: $H_2$, 45.4%; CO, 6.9%; $CO_2$, 1.5%; and $C_2H_2$, 1.1%. The $H_2/CO$ ratio was 6.6, hydrogen yield was 78.8% and energy conversion rate was 63.6%.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.618-622
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• 2007

This paper provides RPF (Refuse Plastics Fuel) gasification characteristics for generating synthesis gas in gasfying reactor which was design in lab-scale. This research is carried out as an immediate work for making pyrolysis gas from RPF into energy resource. This study is consisted of experimental and numerical. The numerical study was accomplished from RPF pyrolysis data, and predicted the maximum operating conditions by STANJAN and FLEUNT. Based on results of STANJAN, it is found that the maximum point of $O_2/O_{2,stoich}$=20${\sim}$30, which is used as injection point of $O_2$. Experiment results shows that CO and $H_2$ were increased but THC was decreased as temperature was increased. It is estimated that the cracking of cracking of THC into CO and H2 is happened at a high temperature. It is observed that as steam was injected, production of CO and H2 were increased, then, H2 is dependent on the amount of injectionsteam.

• 한국연소학회:학술대회논문집
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• 2015.12a
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• pp.73-74
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• 2015

Synthesis gas such as hydrogen and carbon monoxide was produced from $CH_4/oxygen$ mixture using insulated pressurized porous media combustor. Experimentally, two cylindrical SiC foams with the different pore density were piled up in a quartz tube and fully premixed mixture was supplied in the axial direction. After stabilizing fuel-rich flame at the interface of the two foams at several pressure conditions, mole fractions of synthesis gases were measured by gas chromatography. Heat recirculation through the inner foam structure could extend the flow velocity of stable region over the laminar burning velocity. As the pressure increased, the rich flammability limit, $H_2/CO$ ratio, and module M increased.

• Journal of Hydrogen and New Energy
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• v.20 no.4
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• pp.337-343
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• 2009

Noncatalytic partial oxidation of methane for producing synthesis gas was studied in a lab-scale experimental apparatus. Partial oxidation developed for high-temperature, fuel-rich combustion and it is exothermic process. but Steam reforming and Caron reforming is highly endothermic process to need much energy. Noncatalytic partial oxidation of methane is affected by temperature and equivalent ratio, so we studied effect about composition of synthesis gas at lab scale reactor. We used electronic heater to control the temperature of reactor. The quality of synthesis gas is improved and reduced heat value to require at Noncatalytic partial oxidation because the reacting temperature is lower at oxy condition.

• Archives of Metallurgy and Materials
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• v.65 no.3
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• pp.997-1000
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• 2020

With the recent advancement in technology for titanium metal powder injection molding and additive manufacturing, high yield and good flowability powder production is needed. In this study, titanium powder was produced through vacuum induction melting gas atomization with a cold crucible, which can yield various alloy compositions without the need for material pretreatment. The gas behavior in the injection section was simulated according to the orifice protrusion length for effective powder production, and powder was prepared based on the simulation results. The gas distribution changes with the orifice protrusion length, which changes the location of the recirculation zone and production yield of the powder. The produced powders had a spherical morphology, and the content of impurities (N, O) changed with the injected-gas purity.

• Microbiology and Biotechnology Letters
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• v.47 no.4
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• pp.581-584
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• 2019

In this study, the carbon monoxide (CO)-fermenting acetogen, Clostridium sp. AWRP was subjected to chemical mutagenesis with N-methyl-N'-nitro-N-nitrosoguanidine (NTG) to generate a CO-resistant mutant. Among the 26 colonies obtained, the highest alcohol production was observed in one isolate, named C1. Compared to the wild-type strain, the C1 strain exhibited 1.5- and 3.4-fold higher CO consumption rate and alcohol selectivity, respectively. The total CO consumption of strain C1 could be further enhanced by increasing the content of metal ions, such as nickel and iron. The highest ethanol titer (5.7 g/l) was achieved by 5-fold increase in the iron concentration.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.4
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• pp.537-542
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• 2002

A study was conducted to evaluate the nutritive potential value of different aquatic plants: duckweed (Lemna trisulaca), duckweed (Lemna perpusila), azolla (Azolla pinnata) and water-hyacinth (Eichhornia crassipes) from Bangladesh. A wide variability in protein, mineral composition, gas production, microbial protein synthesis, rumen degradable nitrogen and in situ dry matter and crude protein degradability were recorded among species. Crude protein content ranged from 139 to 330 g/kg dry matter (DM). All species were relatively high in Ca, P, Na, content and very rich in K, Fe, Mg, Mn, Cu and Zn concentration. The rate of gas production was highest in azolla and lowest in water-hyacinth. A similar trend was observed with in situ DM degradability. Crude protein degradability was highest in duckweed. Microbial protein formation at 24 h incubation ranged from 38.6-47.2 mg and in vitro rumen degradable nitrogen between 31.5 and 48.4%. Based on the present findings it is concluded that aquatic species have potential as supplementary diet to livestock.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.4
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• pp.542-549
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• 2009

An in vitro study was conducted to determine the effect of nitrate-nitrogen used as a sole dietary nitrogen source on ruminal fermentation characteristics and microbial nitrogen (MN) synthesis. Three treatment diets were formulated with different nitrogen sources to contain 13% CP and termed i) nitrate-N diet (NND), ii) urea-N diet (UND), used as negative control, and iii) tryptone-N diet (TND), used as positive control. The results of 24-h incubations showed that nitrate-N disappeared to background concentrations and was not detectable in microbial cells. The NND treatment decreased net $CH_4$ production, but also decreased net $CO_2$ production and increased net $H_2$ production. Total VFA concentration was lower (p<0.05) for NND than TND. Suppression of $CO_2$ production and total VFA concentration may be linked to increased concentration of $H_2$. The MN synthesis was greater (p<0.001) for NND than UND or TND (5.74 vs. 3.31 or 3.34 mg/40 ml, respectively). Nitrate addition diminished methane production as expected, but also increased MN synthesis.