Landfill Gas Emission Rates Research Articles

Estimation of landfill gas generation in a municipal solid waste disposal site by LandGEM mathematical model

Anaerobic decomposition of organic compounds in landfills is responsible for generation of greenhouse gases. The present study aimed to determine the total gas and methane emission from a landfill located in Hamedan (west of Iran) from 2011 to 2030. LandGEM 3.02 model was used to estimate the gas emission with the volumetric methane percent of 60%, production potential of 107, and methane generation rate of 0.2. Spatial distribution of annual methane and total landfill gas emission rate in the study area at three decades were provided through ArcGIS software. The results showed that organic and food wastes had the maximum amounts in the solid waste stream (over 75%). The results showed that 4.371×108 m3 methane would be produced after 20 years, mostly (4.053×106m3) in the first year. In addition, methane production capacity in Hamedan landfill site was 107 m3/Mg. According to the results, the maximum and minimum gas generation rates are in summer (the hottest season) and winter (the coldest season) respectively. The results of the LandGEM model represented that the total gas and methane generation rates will be significant in the first 10 years. The potential of rapidly degradable organic compounds for gas emission will be higher than that of slowly degradable organic compounds. The results obtained in the present study can be beneficially used in planning for energy production and other applications in landfill sites.

Fire prediction for a non-sanitary landfill “Bubanj” in Serbia

This paper reviews the state of the ?Bubanj? landfill near the City of Nis, Serbia, which has been used for 47 years and which is categorized as a non-sanitary landfill. We utilised the LandGEM 3.02 model, used for estimating landfill gas emission rates, to calculate the amount of landfill gases. Additionally, we measured the amount and composition of landfill gas in section S4 of the landfill from July 2014 to June 2015. We utilised the ALOHA software to estimate the fire-vulnerable zone. The results of our analysis show that the measured average methane emission is higher than the calculated emission. The difference between the measured average emission and calculated emission of methane is logical, as the measurements were performed in an active section, where methane emission higher than in inactive sections is to be expected. Based on the measured methane emissions during one year, we conclude that the methane emission drops as the ambient temperature drops. This paper showcases the state of the ?Bubanj? landfill, which is highly unsatisfactory in terms of environmental and fire protection because of landfill gas generation.

Estimation of greenhouse gas emissions from landfills: application to the Akrotiri landfill site (Chania, Greece)

Landfilling is one of the most common ways of municipal solid waste (MSW) disposal in developing countries. Air pollutants emitted from landfills contributes to the emission in the atmosphere of greenhouse gases and cause serious problems to the human health. Methane emission from landfill is serious environmental global concern as it accounts for approximately 15 percentages of current greenhouse gas emissions. The current study was focused on the determination of air emissions from the Akrotiri landfill site which is located at the Akrotiri area (Chania, Greece). The models used are the triangular model, the stoichiometric model and LandGEM model. These models are used to estimate the total landfill gas production from a given amount of waste. The models differ on their scientific approach for the quantification on emissions, their complexity and input data requirements. The LandGEM model was selected for the determination of more representative assessed landfill gas emission rates. The maximum biogas production rate by the LandGEM model was calculated to be 1.64× 103 Mg yr-1 and was observed during the year 2008 for the A phase of the landfill, while for the B phase the maximum biogas production rate was 2.70 × 103 Mg yr-1 and was observed during 2014.

Solid waste characteristics and their relationship to gas production in tropical landfill

Solid waste characteristics and landfill gas emission rate in tropical landfill was investigated in this study. The experiment was conducted at a pilot landfill cell in Thailand where fresh and two-year-old wastes in the cell were characterized at various depths of 1.5, 3, 4.5 and 6 m. Incoming solid wastes to the landfill were mainly composed of plastic and foam (24.05%). Other major components were food wastes (16.8%) and paper (13.3%). The determination of material components in disposed wastes has shown that the major identifiable components in the wastes were plastic and foam which are resistant to biodegradation. The density of solid waste increased along the depth of the landfill from 240 kg m(-3) at the top to 1,260 kg m(-3) at the bottom. Reduction of volatile solids content in waste samples along the depth of landfill suggests that biodegradation of solid waste has taken place to a greater extent at the bottom of the landfill. Gas production rates obtained from anaerobic batch experiment were in agreement with field measurements showing that the rates increased along the depth of the landfill cell. They were found in range between 0.05 and 0.89 l kg(-1) volatile solids day(-1). Average emission rate of methane through the final cover soil layer was estimated as 23.95 g(-2)day(-1) and 1.17 g(-2)day(-1) during the dry and rainy seasons, respectively.

Measured gas emissions from four landfills in South Africa and some implications for landfill design and methane recovery in semi-arid climates

The magnitude of annual global emissions of methane from municipal solid waste landfills without landfill gas control systems implies that these landfills are significant contributors to the atmospheric load of greenhouse gases. There have been a number of field studies undertaken internationally to measure actual fluxes of methane and carbon dioxide from landfills, with a view to corroborating modelled predictions of the contribution of landfills to the global greenhouse gas budget. The vast majority of these studies have been undertaken in more temperate climates and in developed countries. This paper reports a study of landfill gas emissions from four large landfills located in the semi-arid interior of South Africa. A static accumulation chamber was used and measurements were made at each site over a period of two to three days. The results were analysed by three different methods, all of them leading to the same general conclusion that landfill gas emission rates were lower than expected. A common conclusion based on results from all four sites was that capping of landfills in semi-arid climates with low permeability covers would probably significantly retard the already low rate of waste degradation and thus gas generation. While this may be regarded as advantageous in the short term, it cannot be relied upon in perpetuity as clayey landfill covers will inevitably desiccate and crack in a semiarid environment. In addition, reasonable after-care periods for such landfills are likely to extend well beyond the currently stipulated 30-year period, and efforts to encourage energy recovery from landfills may be hampered because gas generation rates decrease as the waste dries out under conditions of minimal recharge from precipitation. A landfill cover that allows small amounts of percolation of rainfall into the waste may therefore in fact be beneficial in semiarid climates, although care would need to be taken to carefully regulate this infiltration.

Flux Chamber Design and Operation for the Measurement of Municipal Solid Waste Landfill Gas Emission Rates

This paper describes a hybrid Flux Chamber-Soil Gas Probe methodology for measuring municipal solid waste (MSW) gas emission rates. Following the design of the flux chamber, the chamber was laboratory tested to define its mixing characteristics and optimum operating parameter values. Flux chamber operating parameters included: chamber pressure, sweep air flow rate, landfill surface insertion depth, and sweep air velocity. Optimum operating parameter values were determined by operating the flux chamber on a simulated subsurface emission source and varying the operating parameters. The laboratory tests indicated that the flux chamber could be operated to provide zero biasing of gas emission rates, resulting in accurate measurement of gas emission rates.