• Journal of Korea Soil Environment Society
• /
• v.3 no.3
• /
• pp.75-86
• /
• 1998

This paper is going to show the way we can sample the landfill gases flowing out to the air through final cover soil by using an closed chamber in the field for a short time. In addition, we came to the following results through the application of model with actual measurements. 1) Analyzing changes of concentration in the chamber(H: 10-30cm) every 5 minutes, considering analysis time of gas chromatograph for an half hour. 2) The proportion of $CE_4$to $CO_2$changes rapidly near the surface of final cover soil by the influence of methane oxidation reaction. 3) When flux of landfill gas is F=$10^{-5}$mol/$\textrm{m}^2$.s), methane oxidation reaction has an influence on composition of gases, however there is little influence when F=$10^{-6}$ mol/($\textrm{m}^2$.s).

• Journal of the Korean Institute of Gas
• /
• v.25 no.4
• /
• pp.36-42
• /
• 2021

When the landfill gas generated at the landfill site is released into the atmosphere, methane gas with a high global warming potential is emitted, which adversely affects climate change. When methane contained in landfill gas is used as fuel for internal combustion engines and burned to generate electricity, it is emitted into the atmosphere in the form of carbon dioxide, which can contribute to lowering the global warming potential. Therefore, in order to use the landfill gas as fuel for power generation using an internal combustion engine, it is important to increase the thermal efficiency of the engine. Thus, it is necessary to use a fuel supply system in which gas is injected using an electronically controlled injector at an intake port for each cylinder rather than a fuel supply technology using the conventional mixer technology. In order to use the electronically controlled gas injection method, it is important to accurately measure the mass flow rate according to the conditions of using landfill gas. For this, a study was conducted to measure the injection amount and calculate them in order for the intake port gas injection of landfill gas.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.19 no.3
• /
• pp.44-53
• /
• 2011

Siloxane, organo-silicon compound, is used in the various forms of products such as cosmetics and detergents due to its quality physical chemistry attributes. Siloxane included in landfill gas which is caused in the process of decomposing of such products after landfill has imposed negative impacts on the operation of landfill gas utility facilities. The objective of this study was to investigate the siloxane production characteristics depending on the features of various landfill site in Korea so that the analysis was made on the landfilling age and landfill waste by in terms of its concentration, structure and composition. As for the concentration of siloxane depending on time passage, 12 landfill sites were reviewed by landfilling age. As for production attributes change of siloxane by landfill wastes, the source of wastes, physical production ration and siloxane concentration were compared in 6 landfills. The average concentration of total-siloxane within LFG is $6.75mg/m^3$ and cyclic-siloxane out of it occupies over 93%. By element, D4 and D5 in order take the highest proportion regardless of total-siloxane concentration and landfilling age. Even though this study is not able to verify the different impact of each kind of wastes on the generation of siloxane, it is confirmed that total-siloxane and cyclic-siloxane decrease in line with the increase of landfilling age as it does in the first order decay model for landfill gas.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.26 no.2
• /
• pp.19-32
• /
• 2018

This study has been carried out to analyze the effects of leachate recirculation on methane gas concentration in the Landfill. The monthly average on precipitation of the landfill area during the period from 2010 to 2016 has been recorded at 130.9 mm and the total precipitation was recorded at 73.7 mm for the month of June in 2017. And based on the Korea meterological administration data obtained, the water content has been anticipated to be at low level. And for the control environment testing on the effects of leachate recirculation, the reading has been carried out in relation to the methane gas concentration with the landfill site tested with average reading of 30.14%. Once the reading has been established 5 tones of leachate has been injected and the readings carried out respectively with the first reading recorded at 24.66% on June with subsequent readings carried out, 31.51 (6/24), 36.88% (7/1) and final reading carried out on 7/25 registered at 52.47%. Based on the leachate recirculation, the test showed increase of methanate concentrations with the concentration percentage showing between 50~65%.

• Journal of the Korean GEO-environmental Society
• /
• v.15 no.5
• /
• pp.5-11
• /
• 2014

In this study, greenhouse gas emission for small scale landfill (H and Y landfill) was investigated to deduce special the methane generation rate constant(k). To achieve the purpose, the data of physical composition was collected and amount of LFG emission was calculated by using FOD method suggested in 2006 IPCC GL. Also, amount of LFG emission was directly measured in the active landfill sites. By comparing the results, the methane generation rate constant(k), which was used as input variable in FOD method suggested in 2006 IPCC GL, was deduced. From the results on the physical composition, it was shown that the ranges of DOC per year in H (1997~2011) and Y (1994~2011) landfill sites were 13.16 %~23.79 % ($16.52{\pm}3.84%$) and 7.24 %~34.67 % ($14.56{\pm}7.30%$), respectively. The DOC results showed the differences with the suggested values (= 18 %) in 2006 IPCC GL. The average values of methane generation rate constant(k) from each landfill site were $0.0413yr^{-1}$ and $0.0117yr^{-1}$. The results of methane generation rate constant(k) was shown big difference with 2006 IPCC GL defualt value (k = 0.09). It was confirmed that calculation results of greenhouse gas emission using default value in 2006 IPCC GL show excessive output.

• Journal of the Korean GEO-environmental Society
• /
• v.5 no.1
• /
• pp.27-34
• /
• 2004

The reclaimed waste layer in a completed refuse small landfill site was stabilized by JSP(Jumbo Special Pattern System) method. There were some variations of landfill gases(LFGs) after the stabilization. This study investigated the landfill gases emitted from a open dumping landfill site. We measured concentration of landfill gases before and after the construction, and 28 months later. As a result, the concentrations of $H_2S$ and $NH_3$ gases before the construction were 123.51ppm and 171.54ppm, respectively. These values were higher than TWA(Time Weighted Average) values. But the concentrations of $H_2S$ and $NH_3$ gases after the construction were 55.59ppm and 20.51ppm, and they also decreased 9.04ppm and 11.82ppm in 28 months. $CH_4$ and other landfill gases after the construction were little or a little detected in the landfill site. Hence we found out that concentrations or classes of landfill gases causing some problems extremely decreased by way of the stabilization.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.37 no.8
• /
• pp.733-741
• /
• 2013

This is the first paper on the combustion characteristics of landfill gas in a constant volume combustion chamber for a large displacement volume commercial engine, and it discusses the fundamental characteristics of fuel from the viewpoint of thermochemistry and thermodynamics and compares these results with experimental ones. The results show that the final pressures obtained from theoretical analysis vary under the same heating value owing to the change in the constant volume specific heat owing to the difference in the burned gas composition according to the fuel gas compositions; furthermore, the stoichiometric ratios and trends of analytical and experimental pressures coincide very well, although some minor differences are observed between the two. The root cause of the difference is the heat transfer, which changes the specific heat and lowers the temperature considerably, in the real combustion process. In addition, the large chamber volume and ignition position promote the heat transfer to the wall. Finally, the fuel conversion efficiency increases as the methane mol fraction decreases, and it is maximum when the stoichiometric ratio ranges from 0.8 to 0.9. These increases due to the composition and stoichiometric ratio could sufficiently compensate the decrease due to the specific heat ratio drop, LFG might be more advantageous than pure methane in a real engine.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.14 no.2
• /
• pp.63-70
• /
• 2006

The purpose of this study was to develop the stability index of landfill sites to assess it's degree of stability. In order to develop the stability index, field data including leachate qualities, Landfill gas (LFG) composition and element composition of wastes from 50 closed landfills were collected. Three parameters-BOD/CODcr among leachate quality parameters, $CH_4$ among landfill gases, and C/N ratio from wastes-were found to be the best parameters for measuring the stability of landfill sites. The trend line of these parameters were used to Also, $CH_4$ from landfill gases and C/N ratio from wastes were found to be the best parameters. The trend lines of these parameters were used to develop the stability index of landfill sites. The equation for the index was as following; $I_{LS}=S_L+S_G+S_W$ $S_L=-\{4.892+16.587{\cdot}ln[BOD/COD_{Cr]\}$ $S_G=53.872-12.782{\cdot}ln[CH_4]$ $S_W=79.382-20.013{\cdot}ln[C/N]$ (The maximum score for $S_L$, $S_G$, and $S_W$ was 33.3.) where, $I_{LS}$ : The stability index of the landfill $S_L$ : The stability score of the leachate $S_G$ : The stability score of the landfill gas $S_W$ : The stability score of the waste.

• 한국신재생에너지학회:학술대회논문집
• /
• 2010.06a
• /
• pp.244.1-244.1
• /
• 2010

Bio energy development by using Low Calorific Gas Turbine(LCGT) has been developed for New & Renewable energy source for next generation power system, low fuel and operating cost method by using the renewable energy source in landfill gas (LFG), Food Waste, water waste and Livestock biogas. Low calorific fuel purification by pretreatment system and carbon dioxide fixation by green house system are very important design target for evaluate optimum applications for bio energy. Main problems and accidents of Low Calorific Gas Turbine system was derived from bio fuel condition such as hydro sulfide concentration, siloxane level, moisture concentration and so on. Even if the quality of the bio fuel is not better than natural gas, LCGT system has the various fuel range and environmental friendly power system. The mechanical characterisitics of LCGT system is a high total efficiency (>70%), wide range of output power (30kW - 30MW class) and very clean emmission from power system (low NOx). Also, we can use co-generation system. A green house designed for four different carbon dioxide concentration from ambient air to 2000 ppm by utilizing the exhaust gas and hot water from LCGT system. We look forward to contribute the policy for Renewable Portfolio Standards(RPS) by using LCGT power system.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.29 no.2
• /
• pp.5-14
• /
• 2021

As the implementation of carbon reduction measures would be monitored starting from 2023 in line with the Paris Agreement, it is crucial and urgent to control GHGs emitted from wastes contributing to 11% of methane emissions. Despite such importance and urgency, 93% of wastes are deposited in unsanitary landfills in developing countries, presenting challenges to methane management. Against the backdrop, landfill gas-to-energy projects have once again drawn attention for their economic substantiality secured through CDM projects while there has been much research actively carried out to estimate methane emissions and GHG reductions in landfills located in developing countries. Although a signifiant difference was found between estimations calculated based on research methodologies and actual results monitored through registered CDM projects, there has not been a study conducted on what is causing such a difference. Accordingly, the research team conducted an analysis of 18 LFG projects out of 46 that were registered as LFG CDM projects under the UNFCCC and has identified precipitation(28%), malfunction(22%), organic content(11%), amount of landfilled waste(11%) and temperature(11%) as key parameters causing the difference between the amount of methane captured and the amount of GHG reduced.