• Korean Journal of Soil Science and Fertilizer
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• v.46 no.6
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• pp.575-578
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• 2013

Rice cultivation in the paddy field and the burning of crop residues have been identified as the important sources of methane emission in agricultural sector. This study aimed at assessment of the methane emission from croplands in the year of 2011 with the IPCC guideline methodology. Methane from rice cultivation was emitted 6,813 $CO_2$-eq Gg in 2011. According to the water management, methane emission amounts by continuously flooded and intermittently flooded were 1,499 and 5,314 $CO_2$-eq Gg, respectively. Methane emission by crop residues burning was highest in red pepper and followed by rice straw, pulses and barely in 2011. Methane emission by field burning was very little compared with rice cultivation.

• Journal of Soil and Groundwater Environment
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• v.15 no.5
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• pp.40-45
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• 2010

In this study, methane production by reuse of screened soil of landfill was estimated and the effect of application of landfarming for the reduction of methane was investigated. The study soil sampled from S closed landfill contains VS 9.8~12.8% and its BOD/COD is 0.31~0.33 which is more than three times over 0.1, the BOD/COD stabilization criteria of Ministry of Environment. The effective remediation technology for the reduction of organics of soil, landfarming was applied to the screened soil for 60 days. VS and TPH removal showed 5.2~8.3% and 67~74% respectively, and the reduction of VS until 30 day charged 70% of the total reduction. BMP test showed 27.77~30.46 mL $CH_4$/g VS and total methane production from total screened soil for remediation is expected about 260.4 $CH_4$ ton. Expected amount of methane production of the screened soil by landfarming application is 12.9 $CH_4$ ton, which shows 95% gas reduction effect and landfarming is effective for the reduction of methane production from screened soil of landfill.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.761-764
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• 2009

The thermocatalytic decomposition of methane is an environmentally attractive approach to $CO_2$-free production of hydrogen. The fluidized bed was proposed for the continuous withdraw of product carbon from the reactor. The usage of carbon black was reported as stable catalyst for decomposition of methane. Therfore, carbon black (DCC-N330) is used as catalyst. A fluidized bed reactor made of quartz with 0.055 m I.D. and 1.0 m in height was selected for the thermo-catalytic decomposition. The porpane-containg methnae decomposition reaction was operated at the temperature range of 850-900 $^{\circ}C$ methane gas velocity of 1.0 $U_{mf}$ and the operating pressure of 1.0 atm. In this work, propane was added as reactant to make methane conversion higher. Therefore we compared with methane conversion and pre-experiment methane conversion that using only methane as reactant. The carbon black, after experiment, was measured in particle size and surface area and analyzed surface of the carbon black by TEM.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.3
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• pp.212-217
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• 1996

Investgated in relation to Methane emission on dry seeded rice culture was flooding and intermittent irrigation and application time of rice straw in clayey soil. Negative peaks of the methane emission before 3 leaves stage which were never seen in the transplanting cultivation was found and the highest peak was come out at the heading stage. Total amount of emitted methane was lower about 40% than that of the transplanted. Methane emission decreased about 19% by intermittent irrigation. Compost and NPK application reduced methane about 70% and 80% in comparisin with rice straw. Rice straw application one month before sowing reduced methane emission than the application just before sowing.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.3
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• pp.299-306
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• 2008

This study has been conducted to derive the bio-energy, hydrogen and methane production, from mixture of food wastewater and swine wastewater, the high strength organic wastewater and to increase effluent quality. To overcome this limitation in one-phase anaerobic process, two-phase anaerobic process combining hydrogen fermenter and methane fermenter was applied. In this system $2,323ml\;H_2/L$ was produced daily from Run II where 500 ml of heattreated sludge in methane fermenter was injected, and methane produced from methane fermenter did not show big difference regardless of the amount of returning sludge at each Run. It was concluded that the two-phase anaerobic process was the appropriat process to produce hydrogen and methane simultaneously and stably. Influent $TCOD_{Cr}$ to two-phase anaerobic process showed the range of 132~145 g/L(average 140 g/L), and effluent $TCOD_{Cr}$ range was 25~40 g/L(average 32 g/L), and organic removal efficiency showed 71~82%(average 76.3%).

• Transactions of the Korean Society of Mechanical Engineers B
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• v.31 no.11
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• pp.942-948
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• 2007

Popular techniques for producing hydrogen by converting methane include steam reforming and catalyst reforming. However, these are high temperature and high pressure processes limited by equipment, cost and difficulty of operation. Low temperature plasma is projected to be a technique that can be used to produce high concentration hydrogen from methane. It is suitable for miniaturization and fur application in other technologies. In this research, the effect of changing each of the following variables was studied using an AC GlidArc system that was conceived by the research team: the gas components ratio, the gas flow rate, the catalyst reactor temperature and voltage. Results were obtained for methane and hydrogen yields and intermediate products. The system used in this research consisted of 3 electrodes and an AC power source. In this study, air was added fur the partial oxidation reaction of methane. The result showed that as the gas flow rate, the catalyst reactor temperature and the electric power increased, the methane conversion rate and the hydrogen concentration also increased. With $O_2/C$ ratio of 0.45, input flow rate of 4.9 l/min and power supply of 1 kW as the reference condition, the methane conversion rate, the high hydrogen selectivity and the reformer energy density were 69.2%, 32.6% and 35.2% respectively.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.549-552
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• 2009

Methane hydrate is crystalline ice-like compounds which formed methane gas enters within water molecules composed cavity at specially temperature and pressure condition, and water molecule and each other from physically-bond. $1m^3$ hydrate of pure methane can be decomposed to the maximum of $172m^3$ at standard condition. If these characteristics of hydrate are reversely utilized, natural gas is fixed into water in the form of hydrate solid. Therefore the hydrate is considered to be a great way to transport and store natural gas in large quantity. Especially the transportation cost is known to be 18~24% less than the liquefied transportation. However, when methane hydrate is formed artificially, the amount of consumed gas is relatively low due to a slow reaction rate between water and methane gas. In this study, for the better hydrate reaction rate, there is make nano fluid using ultrasonic dispersion of carbon nano tube. and then, Experiment with hydrate formation by nano fluid and methane gas reaction. The results show that when the carbon nano tubes of 0.004 wt% was added to pure water, the amount of consumed gas was about 300% higher than that in pure water and the hydrate formation time decreased.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.2
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• pp.487-492
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• 2008

In this paper, Thermocatalytic decomposition of methane in a fluidized bed reactor (FBR) was studied. The technical approach is based on a single-step decomposition of methane over carbon catalyst in air/water vapor free environment. The factors affecting methane decompostion catalyst activity in methane decomposition reactions were examined. The fluidization phenomena in a gas-fluidized bed of catalyst was determined by the analysis of pressure fluctuation properties, and the results were confirmed with characteristics of methane decomposition. The effect of parameters on the H2 yield was examined for methane decompostion. The decompstion rate was affected by the fluidization quality such as mobility, U-Umf, carbon attrition, elutriation and effectiveness density of fluidization gas.

• KSBB Journal
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• v.18 no.6
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• pp.473-478
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• 2003

The purpose of this study is to look for the optimal conditions of methane production. The conditions tested for methane production enhancement were temperature, pH, carbon source, nitrogen source, and inhibitor which can affects methane production. As a result, optimal conditions for methane production were 30$^{\circ}C$, neutral pH, methanol as a carbon source, NH$_4$Cl as a nitrogen source. 2-Bromoethanesulfonic acid was used as an inhibitor which can affects methane production. Existence in broth less than 10mM, inhibited methane production. Organic acid measurements revealed that formic acid exists in broth as majority.

• Environmental Engineering Research
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• v.21 no.1
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• pp.69-73
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• 2016

Generation of food waste is a serious issue that needs to be addressed worldwide. Developing suitable treatment methods while generating energy (methane) is a common practice for sustainable treatment of waste. In this study, methane generation by food waste was investigated in mesophilic and thermophilic regimes at various hydraulic retention times (HRTs) and organic loading rates (OLR). In temperature regimes, influent concentrations and HRTs ranged from 30 to 110 g COD/L and 18 to 30 days, respectively, which corresponding to an OLR of 1.0 to $6.1kg\;COD/m^3-d$. Better methane production and organic removal was observed under thermophilic conditions because of the enhanced hydrolysis of complex polymers and microbial activity at higher temperature. The peak methane productivities attained in thermophilic and mesophilic regimes were 1.30 and $0.99m^3/m^3-d$, respectively. The maximum methane yields were achieved at 50 g COD/L and HRT of 24 d in both cases, and the values were 264 and $221m^3/ton$ COD, respectively. The results of this study will facilitate the development of sustainable methane production technologies using food waste as a feedstock.