Oxidation of Methane in Landfill Covers: A Strategy to Maximize Energy Revenue PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Oxidation of Methane in Landfill Covers: A Strategy to Maximize Energy Revenue PDF full book. Access full book title Oxidation of Methane in Landfill Covers: A Strategy to Maximize Energy Revenue by . Download full books in PDF and EPUB format.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Yolo County, CA is planning to optimize landfill gas collection by collecting gas during times of peak power demand and storing gas in the landfill during off peak periods by reducing the vacuum on the gas collection system. The objective of this research was to evaluate the efficacy of this approach by evaluating whether gas emissions would increase at low vacuum. Biologically active covers composed of compostD ood chips (80D 0), pure compost, or green waste at thicknesses of 0.31 to 0.9 m were tested using static chambers to measure methane emissions and oxidation potential during rainy and dry season. In addition, laboratory column tests were conducted with two year old green waste to evaluate the effects of pressure gradient, moisture addition to simulate the dry and rainy seasons in California, and continuous vs. intermittent methane feed. The effect of climate was significant. In the field, the highest CH4 emission was 20.85 gm CH4D 2-d in 0.91 m compost + wood chips and 5.255 gm CH4D 2-d in 0.31 m soil during the rainy and dry seasons, respectively. When CH4 oxidation was measured using stable isotopes, it varied from 5 to over 99%. In the rainy season tests, there was a statistically significant decrease in CH4 emissions when the gas system vacuum was increased for the covers with the highest emissions (0.91 m compost + wood chips, 0.31 m compost, soil). In contrast, there was not an increase in CH4 emissions associated with reduced gas collection system vacuum during the dry season tests. The average flux rate in dry season was below 5.255 gm CH4D 2-d in all the covers both for low and high vacuum. While there were many confounding issues, emissions at low vacuum during the rainy season were the highest. Overall, all covers tested were effective in controlling gas release. The emissions data are consistent with the soil gas profile data where CH4 concentrations for the dry season were in the ppmv range while the corresponding c.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Yolo County, CA is planning to optimize landfill gas collection by collecting gas during times of peak power demand and storing gas in the landfill during off peak periods by reducing the vacuum on the gas collection system. The objective of this research was to evaluate the efficacy of this approach by evaluating whether gas emissions would increase at low vacuum. Biologically active covers composed of compostD ood chips (80D 0), pure compost, or green waste at thicknesses of 0.31 to 0.9 m were tested using static chambers to measure methane emissions and oxidation potential during rainy and dry season. In addition, laboratory column tests were conducted with two year old green waste to evaluate the effects of pressure gradient, moisture addition to simulate the dry and rainy seasons in California, and continuous vs. intermittent methane feed. The effect of climate was significant. In the field, the highest CH4 emission was 20.85 gm CH4D 2-d in 0.91 m compost + wood chips and 5.255 gm CH4D 2-d in 0.31 m soil during the rainy and dry seasons, respectively. When CH4 oxidation was measured using stable isotopes, it varied from 5 to over 99%. In the rainy season tests, there was a statistically significant decrease in CH4 emissions when the gas system vacuum was increased for the covers with the highest emissions (0.91 m compost + wood chips, 0.31 m compost, soil). In contrast, there was not an increase in CH4 emissions associated with reduced gas collection system vacuum during the dry season tests. The average flux rate in dry season was below 5.255 gm CH4D 2-d in all the covers both for low and high vacuum. While there were many confounding issues, emissions at low vacuum during the rainy season were the highest. Overall, all covers tested were effective in controlling gas release. The emissions data are consistent with the soil gas profile data where CH4 concentrations for the dry season were in the ppmv range while the corresponding c.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
The overall objective of this project, 'Strategies to Optimize Microbially-Mediated Mitigation of Greenhouse Gas Emissions from Landfill Cover Soils' was to develop effective, efficient, and economic methodologies by which microbial production of nitrous oxide can be minimized while also maximizing microbial consumption of methane in landfill cover soils. A combination of laboratory and field site experiments found that the addition of nitrogen and phenylacetylene stimulated in situ methane oxidation while minimizing nitrous oxide production. Molecular analyses also indicated that methane-oxidizing bacteria may play a significant role in not only removing methane, but in nitrous oxide production as well, although the contribution of ammonia-oxidizing archaea to nitrous oxide production can not be excluded at this time. Future efforts to control both methane and nitrous oxide emissions from landfills as well as from other environments (e.g., agricultural soils) should consider these issues. Finally, a methanotrophic biofiltration system was designed and modeled for the promotion of methanotrophic activity in local methane 'hotspots' such as landfills. Model results as well as economic analyses of these biofilters indicate that the use of methanotrophic biofilters for controlling methane emissions is technically feasible, and provided either the costs of biofilter construction and operation are reduced or the value of CO2 credits is increased, can also be economically attractive.
Author: Niloofar Parsaeifard
Publisher:
ISBN:
Category : Global warming
Languages : en
Pages : 208
Get Book Here
Book Description
Methane (CH4) is one of the major greenhouse gases (GHG) generated in landfills and has a global warming effect 28 times more than carbon dioxide (CO2). Therefore, decreasing methane emissions into the atmosphere from landfills is critically important. In the upper portions of a landfill cover, methane is exposed to oxygen and oxidized aerobically to carbon dioxide while passing through the cover soil; this lowers the overall contribution of the landfill to climate change. However, because of the low permeability of the landfill cover, no aerobic oxidation occurs in the bottom of the cover because oxygen cannot penetrate to those depths. One possibility for increasing the overall oxidation of methane through landfill covers is to increase anaerobic oxidation of methane (AOM) in the lower depths. Although AOM has been studied by previous researchers in fresh water, sea water, and peat soil, no previous study has focused on AOM in landfill cover soil.In this study, anaerobic oxidation of methane (AOM) in the landfill cover soil was studied.Specific objectives were: 1. To evaluate the ability of alternate electron acceptors (besides oxygen) to facilitate anaerobic methane oxidation in clay soil, using batch tests. Different concentrations of the electron acceptors such as sulfate, nitrate, and iron were evaluated. 2. To study the effect of environmental conditions such as different moisture contents,nutrients, and methane concentrations on anaerobic oxidation of methane through batch tests, as well as the effect of methane generation inhibitor. 3. Using the most promising electron acceptor concentrations determined from Objective 1,to measure rates of anaerobic oxidation of methane in clay landfill covers via column tests, which includes realistic conditions of gas flow, cover thickness, and cover compaction. Compaction, permeability, sieve, hydrometer, liquid limit, plastic limit, and electronspectroscopy for chemical analysis tests were conducted to characterize the soil. Batch tests were conducted in 125 mL glass Wheaton bottles with 17 g soil. Electron acceptors (red mud containing iron, iron chloride, iron oxide, hematite, sodium nitrate, potassium nitrite, sodium sulfate, manganese oxide, and ammonium chloride) were added to the soil, along with water(20% or 47% moisture content), nutrient solution, and/or methane generation inhibitor, as appropriate. After flushing the reactors with nitrogen gas, landfill gas (LFG) (50% methane, 50%carbon dioxide) was injected. Methane concentration in the headspace of the reactors was measured over time using a gas chromatograph. Maximum oxidation rate was also calculated using Michaelis-Menten kinetics. Batch tests results showed that sulfate, nitrate, and a combination of sulfate+iron could remove more methane compared to the control test over the long-term and had higher maximum oxidation rates. Hence, they were chosen for testing in columns. Moreover, according to the batch tests, methane removal decreased in the reactors with no added nutrients, lower moisture content, and low initial concentration of methane. The results also showed that adding inhibitor increased methane removal in some reactors while it lowered AOM in other reactors.In columns, the soil was compacted to create a 2-foot layer of cover soil. Methane entered the column at a flux of 179.4 gCH4 m-2 day-1 from the bottom and passed through the cover.Oxidation rate was obtained by measuring methane concentration at the port, where gas entered the column, and at the end of the anoxic zone.The results of column tests showed that at a higher landfill gas flow rate, there was no significant difference in methane removal in the anoxic zone of the columns; however, at a lower flow rate, methane removal in the column amended with sulfate + iron had the highest (around 10%) removal of methane in the anoxic zone, followed by the column that contained sulfate. The results showed H2S gas at the headspace of these two columns, which indicated that sulfate reducing bacteria were likely responsible for methane removal in the anoxic zone of the columns.
Author: Hossain Mohammad Muyeed-Ul- Azam
Publisher:
ISBN:
Category :
Languages : en
Pages : 87
Get Book Here
Book Description
Keywords: Biocover, Methane Oxidation, Gas Collection System.
Author: James Nelson Tyree
Publisher:
ISBN:
Category :
Languages : en
Pages : 146
Get Book Here
Book Description
Countries around the world face social, economic, and ecological damage from escalating natural disasters caused by climate change. In an effort to curtail climate change impacts, local and regional governments are beginning to employ green house gas (GHG) mitigation strategies to reduce their carbon footprint. These strategies work to eliminate a range of GHG emissions from entering the atmosphere. Apart from carbon dioxide (CO2), the most prevalent GHG is methane. In terms of global warming, methane is approximately 21 times more harmful to the atmosphere than CO2. Natural gas systems, coal mining, manure management, rice cultivation, wastewater treatment, and landfills all contribute to methane generation. According to the US Environmental Protection Agency's 2011 US GHG inventory, landfills generate 1.5% of total GHG emissions in carbon dioxide equivalents. Recognizing the global impacts of its policies and operations, municipalities are working to reduce their GHG emissions. Coalitions like the C40 Cities Climate Leadership Group were created to specifically address GHG reductions, which will result in a 248 million MT reduction in GHGs released to the atmosphere by 2020. Guided by existing literature, this Master's Report calculates methane generation and transport to determine the effectiveness of applying two methane mitigation alternatives--passive methane oxidation biocovers (PMOBs) and landfill gas to energy technologies (LFGTE)--at an inactive landfill site to reduce GHG emissions. LFGTE generates energy for direct use such as space heating or industrial processes or for electricity generation. Cost-saving strategies abound for landfills which utilize LFGTE. PMOBs optimize the landfill surface soil cover environment to promote microbial growth of bacteria, called methanotrophs, which convert methane into carbon dioxide. When employed, these mitigation alternatives are designed to significantly reduce methane emissions from landfills. The EPA has developed a computer modeling program (LANDGEM) to aid in the calculation of landfill gas generation. A hypothetical case study of a one million ton landfill was created and modeled for methane generation over a 35 year period. With methane generation rates calculated, assessment of potential LFGTE was performed and methane oxidation rate calculations were made to determine the impact of a PMOB and LFGTE on net GHG emissions at the landfill. The overall GHG reductions with these engineering controls were two-thirds of the level a landfill without controls would emit. These results indicate that implementing methane mitigation steps at closed landfills throughout the world would yield significant reductions in GHG emissions.
Author: Lei Yuan
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
ABSTRACT: This dissertation presents the work of investigating methane emission and oxidation through landfill covers. Methane as a major source of greenhouse and is being emitted from solid waste landfill at a tremendous rates. These emissions could be mitigated by methanotrophic bacteria in enriched and non-enriched soil covers.
Author: Muna AlBanna
Publisher:
ISBN:
Category : University of Ottawa theses
Languages : en
Pages : 344
Get Book Here
Book Description
Author: Gunnar Borjesson
Publisher: Coronet Books
ISBN: 9789157652980
Category : Landfill gases
Languages : en
Pages : 110
Get Book Here
Book Description
Author: Julie Thea Thomsen
Publisher:
ISBN:
Category :
Languages : en
Pages : 43
Get Book Here
Book Description
Author: Hilary A. Jones
Publisher:
ISBN:
Category :
Languages : en
Pages : 362
Get Book Here
Book Description
