• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.185.1-185.1
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• 2011

본 연구는 중 소규모 매립지가스(LFG)의 활용을 위한 가스고체화(Gas-To-Solid) 기술개발을 목적으로 하고 있다. LFG는 환경적인 문제로 인하여 소각 등의 방법으로 처리하고 있으나, 약 5,000kcal/$m^3$의 높은 발열량과 일반적으로 매립 후 20~30년 후까지 지속적인 발생특성으로 안정적인 공급이 가능한 신재생에너지원으로 활용될 수 있다. LFG 자원화 할 경우 발전 및 중질가스 등으로 활용하는 것이나, 중소규모 매립장의 경우 경제성 등의 문제로 자원화하지 못하고 태워지거나 방치되고 있다. 본 연구에서는 LFG의 저장과 수송 기술 중 GTS 기술을 통하여 저장과 수송에 제약이 크고 많은 비용이 소비되는 기체 상태의 에너지원을 하이드레이트화 시킴으로서 중 소규모 매립지에서 상대적으로 적은 비용으로 가스저장과 지상수송이 가능하게 할 수 있다. 본 연구의 결과로 LFG 에너지화 실증화 플랜트를 설계/제작 하였으며, 메탄+이산화탄소+물 하이드레이트 형성 실험을 통해 4.56 Mpa, 277.2 K 조건에서 3시간을 한 사이클로하는 공정운전을 가지는 것을 확인하였다.

• Journal of the Korea Safety Management & Science
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• v.3 no.3
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• pp.201-211
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• 2001

The most general treatment method of municipal solid waste is a landfill. The LFG (landfill gas) migration is a serious problem in environmental aspect. The object of this study is to present the possibility of LFG utilization as a replacement or supplementary fuel for local energy -demand. We have developed the EXCEL program for the economic analysis.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.461-468
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• 2004

The amount of $CO_2$ and $CH_4$ that were produced during biodegradation with were measured as function of time. Also, the settlements of landfill lysimeters were measured at the same time, and the relation with LFF(landfill gas) production was investigated. The effects of leachate recycle on the acceleration of settlement were studied by comparing two lysimeters. The gas production rate constant, $^{\kappa}_{LFG}$ is obtained to predict future gas production and settlement. These will be key role factors to predict gas production patterns and residual long-term settlement.

• New & Renewable Energy
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• v.6 no.1
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• pp.29-37
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• 2010

Biogas is a carbon neutral energy and consists of mostly methane and carbon dioxide, with smaller amounts of water vapor, and trace amounts of $H_2S$, Siloxane and other impurities. Hydrogen sulfide and Siloxane usually must be removed before the gas can be used for generation of electricity or heat. The goals of this project are to develope the Fuel conditioning system of Land Fill Gas for 30kW-Micro Gas Turbine co-generation system. The fuel conditioning system mainly consists of $H_2S$ removal system, Land Fill Gas compressor, Siloxane removal system and many filtering systems. The fuel requirement of 30kW MGT is at least 32% of $CH_4$, $H_2S$ (<30 ppm), Siloxane (<5ppb) and supply pressure (> 0.6 MPa) from LFG compressor. Main mechnical charateristics of Micro Gas Turbine system by using LFG have the specific performance; 1) high speed turbine speed (96,000 rpm) 2) very clean emmission NOx (<9 ppm) 3) high efficiency of energy conversion rate. This paper focuses on the development of design technology for LFG fuel conditioning system. The study also has the plan to replace the fuel of gas turbine and other distributed power systems. As the increase of Land Fill Gas (LFG), this system help to contribute to spread more New & Renewable Energy and the establishment of Renewable Portfolio Standards (RPS) for Korea.

• Journal of the Korean Society of Groundwater Environment
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• v.6 no.2
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• pp.101-106
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• 1999

Open dump of refuse causes groundwater and soil contamination by leachate and air pollution by LFG(Landfill Gas). In this paper, in order to perform a study about reduction of high leachate and LFG collection & control, using a 3-D, 2-phase, transient FDM model, the analysis of simultaneous flow of leachate and LFG has been carried out. In present numerical analysis it is assumed that 58 percents of LFG will evaporate to the ambient air and the recharge rate of a landfill be 12 percent of the average precipitation per year. All other data were excerpted at the point of 1995 when three refuse layers had been buried. From numerical analysis we concluded that maximum head value is approximately 26 mH2O<-에이치투오 (2.52 atm) in the center of the system and that installing venting trench plays an important role in landfill stabilization. Evan with the assumption of three layers constructed and low recharge rate applied, it is found that cumulative leachate and LFG productions will be 15.1 million 세제곱미터, 5.58 billion 세제곱미터, respectively after 40 years.

• Food Science of Animal Resources
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• v.29 no.2
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• pp.143-150
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• 2009

This study was carried out to investigate the properties of crude exopolysaccaride (CEPS) produced by Streptococcus thermophilus LFG in goat milk. The yields of CEPS from yogurt cultured with Str. thermophilus LFG were greater at higher temperatures $(40-45^{\circ}C)$ than at lower temperatures $(30-35^{\circ}C)$. Goat milk yogurt had lower viscosity values than cow milk yogurt. However, the CEPS yield was higher in goat milk yogurt than in cow milk yogurt. The yields of CEPS from yogurt were also higher in cultured milk containing 3% glucose (14-21%), and 3% sucrose (4-16%) relative to the control yogurt. Antioxidant activities were higher in goat milk yogurt supernatant (21%) and its CEPS (28%) than cow milk yogurt supernatant (11%) and its CEPS (24%). The amino acid contents of CEPS were higher in yogurt using goat milk than that using cow milk. The CEPS extracted from goat milk yogurt produced by Str. thermophilus LFG consists of carbohydrate (37% w/w) and protein (63% w/w). The CEPS consisted of monosaccharides such as glucose 56.45% (w/w), galactose 42.35% (w/w), galactosamine 1.37% (w/w), glucosamine 1.09% (w/w) and fucose 0.27% (w/w).

• Analytical Science and Technology
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• v.16 no.5
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• pp.407-417
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• 2003

In this study, we measured the concentration of VOCs in ambient air and landfill gas (LFG) in a midsize municipal landfill site. The LFG flux values of VOCs were computed using a total of fifteen VOCs determined by GC-PID system. To understand relative contribution of these 15 VOCs to the total carbon budget, their concentration and flux estimates were compared to those of non-methane hydrocarbons (NMHC) measured concurrently. It was also found that there were systematic differences in absolute VOC concentration levels between LFG and air samples above landfill surface. The VOC concentrations in LFG samples were high enough to reach above a few tens of ppm that are 10 to 100 times higher than those in air above landfill surface. If the LFG flux values were computed using the LFG concentration data of 15 VOCs and NMHC with exit ventilation speed, the magnitude of emissions in the study area is estimated to be 8.6 and 103 ton C/yr, respectively. In the meantime, large fraction of those speciated VOC emissions is accounted for by BTEX.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1998.11a
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• pp.225-231
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• 1998

Open dump causes groundwater and soil contamination by leachate, air pollution by LFG (Landfill Gas). In this paper, in order to improve landfill researches which have been done about reduction of high leachate level and LFG collection in the Kimpo landfill separately, the effect of simultaneous flowing of leachate and LFG has been Studied. The HYLGS (Hanyang Leachate Gas Simulator) used in this study is a 3D, 2-phase, transient FDM model which can be applied to venting trenches in a landfill. From present numerical analysis it can be concluded that all the pressures of the Kimpo landfill grid system are almost the same and their maximum value in the center grid block of the system is approximately 26 m $H_2O$ (2.52 atm), that because the pressures of venting trench layer situated in the middle of the landfill have the lowest values and equal with air pressure, the venting trenches play an important role in landfill stabilization, that the flow of gas will be more difficult as time goes by owing to the increase of LGR(Leachate and gas ratio).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.11
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• pp.1714-1725
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• 1993

This paper analyzes the properties of such algorithm that corresponds to the nonlinear adaptive algorithm with additional update terms, parameterized by the scalar factors a1, a2, a3 and Presents its structure. The analysis of convergence leads to eigenvalues of the transition matrix for the mean weight vector. Regions in which the algorithm becomes stable are demonstrated. The time constant is derived and the computational complexities of MLMS algorithms are compared with those of the conventional LMS, sign, LFG, and QFG algorithms. The properties of convergence in the mean square are analyzed and the expressions of the mean square recursion and the excess mean square error are derived. The necessary condition for the CFG algorithm to be stable is attained. In the computer simulation applied to the system identification the CFG algorithm has the more computation complexities but the faster convergence speed than LMS, LFG and QFG algorithms.

• Journal of Environmental Science International
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• v.19 no.7
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• pp.901-905
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• 2010

Emissions of leachate, odor, and landfill gas(LFG) from an open-dumping landfill site do harm to public health by contaminating neighboring soil, underground water, and rivers. Particularly, methane($CH_4$) and carbon dioxide($CO_2$), the main components of LFG, are especially noted as the causing material of the global warming that become seriously recognized worldwide issue. As one of alternatives in managing LFG, incineration of inflammable wastes that are generated during excavation process at an open-dumping landfill has been evaluated. Standard on stabilization for evaluation, neither $CH_4$ density nor $CO_2$ density could not Because meet 'less than 5%' criterion and so it is right to install a gas collection system during landfill renewal to prevent diffusion of odor and collect it. Because it shows considerable heating value, incineration of inflammable wastes might be the reasonable solution from the result of our study.