WorldWideScience

Sample records for landfill gas generation

  1. Landfill gas

    Energy Technology Data Exchange (ETDEWEB)

    Willumsen, H. (Crone and Koch, Viborg (Denmark))

    1990-08-01

    In most landfills, the refuse deposit usually has a high content of organic matter consisting of a mixture of household, industrial and garden waste. Immediately after the refuse has been placed in the landfill, aerobic decomposition of the organic waste begins. Once the oxygen has been exhausted, anaerobic decomposition begins. 'Biogas' is produced which has a methane content of approximately 50% and can be used as a fuel. The exploitation of landfill gas for energy purposes was initiated in the USA around 1975 and later in Europe. A landfill gas plant consists of a recovery system and a production system. A recovery system can consist of vertical perforated pipe wells, horizontal perforated pipes or ditches, or membrane covers to collect the generated gas. Under normal conditions it will not be necessary to process the gas except for the removal of water and other impurities (e.g. solid particles) if the gas is to be used in a boiler or engine. In the USA most often only power is produced, whereas in Europe the waste heat is normally exploited, making the plant function as a combined power and heating plant. It is also possible to upgrade the landfill gas to a methane content of nearly 100, after which it can be distributed with natural gas. There are several such plants in the USA. 8 refs., 6 figs., 6 tabs.

  2. Fuel Flexibility: Landfill Gas Contaminant Mitigation for Power Generation

    Energy Technology Data Exchange (ETDEWEB)

    Storey, John Morse [ORNL; Theiss, Timothy J [ORNL; Kass, Michael D [ORNL; FINNEY, Charles E A [ORNL; Lewis, Samuel [Oak Ridge National Laboratory (ORNL); Kaul, Brian C [ORNL; Besmann, Theodore M [ORNL; Thomas, John F [ORNL; Rogers, Hiram [ORNL; Sepaniak, Michael [University of Tennessee, Knoxville (UTK)

    2014-04-01

    This research project focused on the mitigation of silica damage to engine-based renewable landfill gas energy systems. Characterization of the landfill gas siloxane contamination, combined with characterization of the silica deposits in engines, led to development of two new mitigation strategies. The first involved a novel method for removing the siloxanes and other heavy contaminants from the landfill gas prior to use by the engines. The second strategy sought to interrupt the formation of hard silica deposits in the engine itself, based on inspection of failed landfill gas engine parts. In addition to mitigation, the project had a third task to develop a robust sensor for siloxanes that could be used to control existing and/or future removal processes.

  3. Estimating methane gas generation from Devil's swamp landfill using greenhouse gas emission models

    Science.gov (United States)

    Adeyemi, Ayodeji Thompson

    Greenhouse gas (GHG) has been a key issue in the study, design, and management of landfills. Landfill gas (LFG) is considered either as a significant source of renewable energy (if extracted and processed accordingly) or significant source of pollution and risk (if not mitigated or processed). A municipal solid waste (MSW) landfill emits a significant amount of methane, a potent GHG. Thus, quantification and mitigation of GHG emissions is an important area of study in engineering and other sciences related to landfill technology and management. The present study will focus on estimating methane generation from Devils swamp landfill (DSLF), a closed landfill in Baton Rouge, LA. The landfill operated for 53 years (1940-1993) and contains both industrial and municipal waste products. Since the Clean Air Act of 1963, landfills are now classified as New Source Performance Standard (NSPS) waste (i.e., waste that will decompose to generate LFG). Currently, the DSLF is being used as source of renewable energy through the "Waste to Energy" program. For this study, to estimate the methane potential in the DSLF, it is important to determine the characteristics and classification of the landfill's wastes. The study uses and compares different GHG modeling tools---LandGEM, a multiphase model, and a simple first-order model---to estimate methane gas emission and compare results with the actual emissions from the DSLF. The sensitivity of the methane generation rate was analyzed by the methane generation models to assess the effects of variables such as initial conditions, specific growth rate, and reaction rate constants. The study concludes that methane (L0) and initial organic concentration in waste (k) are the most important parameters when estimating methane generation using the models.

  4. Recovery Act: Johnston Rhode Island Combined Cycle Electric Generating Plant Fueled by Waste Landfill Gas

    Energy Technology Data Exchange (ETDEWEB)

    Galowitz, Stephen

    2013-06-30

    The primary objective of the Project was to maximize the productive use of the substantial quantities of waste landfill gas generated and collected at the Central Landfill in Johnston, Rhode Island. An extensive analysis was conducted and it was determined that utilization of the waste gas for power generation in a combustion turbine combined cycle facility was the highest and best use. The resulting project reflected a cost effective balance of the following specific sub-objectives. 1) Meet environmental and regulatory requirements, particularly the compliance obligations imposed on the landfill to collect, process and destroy landfill gas. 2) Utilize proven and reliable technology and equipment. 3) Maximize electrical efficiency. 4) Maximize electric generating capacity, consistent with the anticipated quantities of landfill gas generated and collected at the Central Landfill. 5) Maximize equipment uptime. 6) Minimize water consumption. 7) Minimize post-combustion emissions. To achieve the Project Objective the project consisted of several components. 1) The landfill gas collection system was modified and upgraded. 2) A State-of-the Art gas clean up and compression facility was constructed. 3) A high pressure pipeline was constructed to convey cleaned landfill gas from the clean-up and compression facility to the power plant. 4) A combined cycle electric generating facility was constructed consisting of combustion turbine generator sets, heat recovery steam generators and a steam turbine. 5) The voltage of the electricity produced was increased at a newly constructed transformer/substation and the electricity was delivered to the local transmission system. The Project produced a myriad of beneficial impacts. 1) The Project created 453 FTE construction and manufacturing jobs and 25 FTE permanent jobs associated with the operation and maintenance of the plant and equipment. 2) By combining state-of-the-art gas clean up systems with post combustion emissions control

  5. Recovery Act: Brea California Combined Cycle Electric Generating Plant Fueled by Waste Landfill Gas

    Energy Technology Data Exchange (ETDEWEB)

    Galowitz, Stephen

    2012-12-31

    The primary objective of the Project was to maximize the productive use of the substantial quantities of waste landfill gas generated and collected at the Olinda Landfill near Brea, California. An extensive analysis was conducted and it was determined that utilization of the waste gas for power generation in a combustion turbine combined cycle facility was the highest and best use. The resulting Project reflected a cost effective balance of the following specific sub-objectives: • Meeting the environmental and regulatory requirements, particularly the compliance obligations imposed on the landfill to collect, process and destroy landfill gas • Utilizing proven and reliable technology and equipment • Maximizing electrical efficiency • Maximizing electric generating capacity, consistent with the anticipated quantities of landfill gas generated and collected at the Olinda Landfill • Maximizing equipment uptime • Minimizing water consumption • Minimizing post-combustion emissions • The Project produced and will produce a myriad of beneficial impacts. o The Project created 360 FTE construction and manufacturing jobs and 15 FTE permanent jobs associated with the operation and maintenance of the plant and equipment. o By combining state-of-the-art gas clean up systems with post combustion emissions control systems, the Project established new national standards for best available control technology (BACT). o The Project will annually produce 280,320 MWh’s of clean energy o By destroying the methane in the landfill gas, the Project will generate CO2 equivalent reductions of 164,938 tons annually. The completed facility produces 27.4 MWnet and operates 24 hours a day, seven days a week.

  6. Evaluation of potential opportunities for electric power generation from landfill gas at “Tsalapitsa”

    Directory of Open Access Journals (Sweden)

    Ganev Ivaylo

    2014-01-01

    Full Text Available Potential opportunities for electric power generation from landfill gas (LFG utilization were estimated for the second largest landfill site in Bulgaria, situated near the city of Plovdiv. The work performed was based on detailed analysis of experimentally obtained and model-predicted features of the “Tsalapitsa” landfill site. The study presents a short description of the site, the global characteristics of the disposed municipal solid waste, and the experimentally obtained methane composition of the LFG. Based on the above described observations, the potential for LFG recovery at “Tsalapitsa” was determined, together with that for electric power generation for the next 25 years. A set of recommendations was then developed regarding the parameters required for the installation of electric power generation from LFG in Plovdiv.

  7. Landfill gas management facilities design guidelines

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-03-15

    In British Columbia, municipal solid waste landfills generate over 1000 tonnes of methane per year; landfill gas management facilities are required to improve the environmental performance of solid waste landfills. The aim of this document, developed by the British Columbia Ministry of the Environment, is to provide guidance for the design, installation, and operation of landfill gas management facilities to address odor and pollutant emissions issues and also address health and safety issues. A review of technical experience and best practices in landfill gas management facilities was carried out, as was as a review of existing regulations related to landfill gas management all over the world. This paper provides useful information to landfill owners, operators, and other professionals for the design of landfill gas management facilities which meet the requirements of landfill gas management regulations.

  8. Evaluation and application of site-specific data to revise the first-order decay model for estimating landfill gas generation and emissions at Danish landfills

    DEFF Research Database (Denmark)

    Mou, Zishen; Scheutz, Charlotte; Kjeldsen, Peter

    2015-01-01

    Methane (CH4) generated from low-organic waste degradation at four Danish landfills was estimated by three first-order decay (FOD) landfill gas (LFG) generation models (LandGEM, IPCC, and Afvalzorg). Actual waste data from Danish landfills were applied to fit model (IPCC and Afvalzorg) required...... categories. In general, the single-phase model, LandGEM, significantly overestimated CH4 generation, because it applied too high default values for key parameters to handle low-organic waste scenarios. The key parameters were biochemical CH4 potential (BMP) and CH4 generation rate constant (k.......Implications: Landfill operators use the first-order decay (FOD) models to estimate methane (CH4) generation. A single-phase model (LandGEM) and a traditional model (IPCC) could result in overestimation when handling a low-organic waste scenario. Site-specific data were important and capable of calibrating key parameter...

  9. Comparison between landfill gas and waste incineration for power generation in Astana, Kazakhstan.

    Science.gov (United States)

    Inglezakis, Vassilis J; Rojas-Solórzano, Luis; Kim, Jong; Aitbekova, Aisulu; Ismailova, Aizada

    2015-05-01

    The city of Astana, the capital of Kazakhstan, which has a population of 804,474, and has been experiencing rapid growth over the last 15 years, generates approximately 1.39 kg capita(-1) day(-1) of municipal solid waste (MSW). Nearly 700 tonnes of MSW are collected daily, of which 97% is disposed of at landfills. The newest landfill was built using modern technologies, including a landfill gas (LFG) collection system.The rapid growth of Astana demands more energy on its path to development, and the viability analysis of MSW to generate electricity is imperative. This paper presents a technical-economic pre-feasibility study comparing landfill including LFG utilization and waste incineration (WI) to produce electricity. The performance of LFG with a reciprocating engine and WI with steam turbine power technologies were compared through corresponding greenhouse gases (GHG) reduction, cost of energy production (CEP), benefit-cost ratio (BCR), net present value (NPV) and internal rate of return (IRR) from the analyses. Results demonstrate that in the city of Astana, WI has the potential to reduce more than 200,000 tonnes of GHG per year, while LFG could reduce slightly less than 40,000 tonnes. LFG offers a CEP 5.7% larger than WI, while the latter presents a BCR two times higher than LFG. WI technology analysis depicts a NPV exceeding 280% of the equity, while for LFG, the NPV is less than the equity, which indicates an expected remarkable financial return for the WI technology and a marginal and risky scenario for the LFG technology. Only existing landfill facilities with a LFG collection system in place may turn LFG into a viable project.

  10. Landfill gas generation and emission at danish waste disposal sites receiving waste with a low organic waste content

    DEFF Research Database (Denmark)

    Mou, Zishen; Scheutz, Charlotte; Kjeldsen, Peter

    2015-01-01

    two models are multi-phase models, which defines waste fractions into traditional MSW and low-organic waste categories, respectively. Both the LandGEM and the IPCC model estimated significantly larger methane (CH4) generation in comparison to the Afvalzorg model. The Afvalzorg model could better show...... the influence of not only the total disposed waste amount, but also various waste categories, and was found more suitable to estimate LFG generation from landfills receiving low-organic waste. Four major waste categories currently being disposed at Danish landfills (mixed bulky, shredder, dewatered sludge...... results. The LFG generation from four Danish landfills was estimated by the Afvalzorg model using the experimentally based BMP and k values and compared to whole landfill emission rates measured by applying a tracer gas dispersion method. The results showed that the revised modelled LFG generation rates...

  11. Optimization of first order decay gas generation model parameters for landfills located in cold semi-arid climates.

    Science.gov (United States)

    Vu, Hoang Lan; Ng, Kelvin Tsun Wai; Richter, Amy

    2017-08-17

    Canada has one of the highest waste generation rates in the world. Because of high land availability, land disposal rates in the province of Saskatchewan are high compared to the rest of the country. In this study, landfill gas data was collected at semi-arid landfills in Regina and Saskatoon, Saskatchewan, and curve fitting was carried out to find optimal k and Lo or DOC values using LandGEM, Afvalzorg Simple, and IPCC first order decay models. Model parameters at each landfill were estimated and compared using default k and Lo or DOC values. Methane generation rates were substantially overestimated using default values (with percentage errors from 55 to 135%). The mean percentage errors for the optimized k and Lo or DOC values ranged from 11.60% to 19.93% at the Regina landfill, and 1.65% to 10.83% at the Saskatoon landfill. Finally, the effect of different iterative methods on the curve fitting process was examined. The residual sum of squares for each model and iterative approaches were similar, with the exception of iterative method 1 for the IPCC model. The default values in these models fail to represent landfills located in cold semi-arid climates. The use of site specific data, provided enough information is available regarding waste mass and composition, can greatly help to improve the accuracy of these first order decay models. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Pretreated Landfill Gas Conversion Process via a Catalytic Membrane Reactor for Renewable Combined Fuel Cell-Power Generation

    Directory of Open Access Journals (Sweden)

    Zoe Ziaka

    2013-01-01

    Full Text Available A new landfill gas-based reforming catalytic processing system for the conversion of gaseous hydrocarbons, such as incoming methane to hydrogen and carbon oxide mixtures, is described and analyzed. The exit synthesis gas (syn-gas is fed to power effectively high-temperature fuel cells such as SOFC types for combined efficient electricity generation. The current research work is also referred on the description and design aspects of permreactors (permeable reformers carrying the same type of landfill gas-reforming reactions. Membrane reactors is a new technology that can be applied efficiently in such systems. Membrane reactors seem to perform better than the nonmembrane traditional reactors. The aim of this research includes turnkey system and process development for the landfill-based power generation and fuel cell industries. Also, a discussion of the efficient utilization of landfill and waste type resources for combined green-type/renewable power generation with increased processing capacity and efficiency via fuel cell systems is taking place. Moreover, pollution reduction is an additional design consideration in the current catalytic processors fuel cell cycles.

  13. Modified landfill gas generation rate model of first-order kinetics and two-stage reaction

    Institute of Scientific and Technical Information of China (English)

    Jiajun CHEN; Hao WANG; Na ZHANG

    2009-01-01

    This investigation was carried out to establish a new domestic landfill gas (LFG) generation rate model that takes into account the impact ofleachate recirculation. The first-order kinetics and two-stage reaction (FKTSR) model of the LFG generation rate includes mechanisms of the nutrient balance for biochemical reaction in two main stages. In this study, the FKTSR model was modified by the introduction of the outflow function and the organic acid conversion coefficient in order to represent the in-situ condition of nutrient loss through leachate. Laboratory experiments were carried out to simulate the impact of leachate recirculation and verify the modified FKTSR model. The model calibration was then calculated by using the experimental data. The results suggested that the new model was in line with the experimental data. The main parameters of the modified FKTSR model, including the LFG production potential (L0), the reaction rate constant in the first stage (K1), and the reaction rate constant in the second stage (K2) of 64.746 L, 0.202 d-1, and 0.338 d-1,respectively, were comparable to the old ones of 42.069 L,0.231 d-1, and 0.231 d-1. The new model is better able to explain the mechanisms involved in LFG generation.

  14. Using a Gas-Phase Tracer Test to Characterize the Impact of Landfill Gas Generation on Advective-Dispersive Transport of VOCs in the Vadose Zone.

    Science.gov (United States)

    Monger, Gregg R; Duncan, Candice Morrison; Brusseau, Mark L

    2014-12-01

    A gas-phase tracer test (GTT) was conducted at a landfill in Tucson, AZ, to help elucidate the impact of landfill gas generation on the transport and fate of chlorinated aliphatic volatile organic contaminants (VOCs). Sulfur hexafluoride (SF6) was used as the non-reactive gas tracer. Gas samples were collected from a multiport monitoring well located 15.2 m from the injection well, and analyzed for SF6, CH4, CO2, and VOCs. The travel times determined for SF6 from the tracer test are approximately two to ten times smaller than estimated travel times that incorporate transport by only gas-phase diffusion. In addition, significant concentrations of CH4 and CO2 were measured, indicating production of landfill gas. Based on these results, it is hypothesized that the enhanced rates of transport observed for SF6 are caused by advective transport associated with landfill gas generation. The rates of transport varied vertically, which is attributed to multiple factors including spatial variability of water content, refuse mass, refuse permeability, and gas generation.

  15. Landfill gas from environment to energy

    Energy Technology Data Exchange (ETDEWEB)

    Gendebien, A.; Pauwels, M.; Constant, M.; Ledrut-Damanet, M.J.; Nyns, E.J. [Louvain Univ. (Belgium); Fabry, R.; Ferrero, G.L. [Commission of the European Communities, Brussels (Belgium); Willumsen, H.C.; Butson, J.

    1992-11-01

    Landfill gas is an alternative source of energy which can be commercially exploited wherever municipal solid wastes are disposed of in sanitary landfills. In this context, it was decided to launch a comprehensive study on the subject of energy valorization of landfill gas. The main topics dealt with in the study, which is supported by a comprehensive literature survey and six detailed case-studies, include; (i) the environmental impact of landfill gas, (ii) the process of landfill gas genesis and the technology of landfill gas control by its exploitation, (iii) the monitoring of landfill gas emissions, (iv) the policies and legal aspects of landfill gas in the European Community and in the world, (v) the estimation of landfill gas potentials and economics of landfill gas control and exploitation, (vi) the status of landfill gas exploitation in the European Community and in the world. (authors). refs., figs., tabs.

  16. ELECTRIC POWER GENERATION USING A PHOSPHORIC ACID FUEL CELL ON A MUNICIPAL SOLID WASTE LANDFILL GAS STREAM

    Science.gov (United States)

    The report gives results of tests to verify the performance of a landfill gas pretreatment unit (GPU) and a phorsphoric acid fuel cell system. The complete system removes contaminants from landfill gas and produces electricity for on-site use or connection to an electric grid. Th...

  17. Research, development and demonstration in the design of sanitary landfill to optimize the generation and capture of compressible gas

    Science.gov (United States)

    Nosanov, M. E.; Teeple, F. E.; Buesch, S. C.

    1982-02-01

    The influences of selected factors on the generation and recovery of methane gas from sanitary landfills were investigated. The factors included encapsulation, shredding, air classifying, moisture, and pH. Facilities consisting of six model sanitary landfill cells, each with a capacity of approximately 450 cubic yards of municipal waste, and auxiliary subsystems were constructed. Municipal waste in each cell is contained in a 30-mil thick polyvinly chloride plastic sheeting forming a virtually gas-tight envelope. Two cells were filled with as-collected urban waste, two with shredded waste, and two with shredded and air classified waste, constituting three pairs of cells. One of each pair is a control cell with the other used as an experimental variable. Systems were provided for adding measured amounts of water, removing and recirculating leachate, and for extracting gas and measuring gas flow. During testing, gas production and internal cell characteristics were measured to determine the effects of mechanical processing, moisture content, and leachate pH.

  18. Methane Gas Utilization Project from Landfill at Ellery (NY)

    Energy Technology Data Exchange (ETDEWEB)

    Pantelis K. Panteli

    2012-01-10

    Landfill Gas to Electric Energy Generation and Transmission at Chautauqua County Landfill, Town of Ellery, New York. The goal of this project was to create a practical method with which the energy, of the landfill gas produced by the decomposing waste at the Chautauqua County Landfill, could be utilized. This goal was accomplished with the construction of a landfill gas to electric energy plant (originally 6.4MW and now 9.6MW) and the construction of an inter-connection power-line, from the power-plant to the nearest (5.5 miles) power-grid point.

  19. Characterization and Energy Generation of Sharda Landfill at Agra

    Directory of Open Access Journals (Sweden)

    Sohail Ayub

    2014-05-01

    Full Text Available Most of the global municipal solid waste is dumped in non regulated landfills and the generated methane is emitted to the atmosphere which has global warming potential. Some of the modern regulated landfills attempt to capture and utilize landfill gas. An attempt has been made in this study for the recovery of energy potential of Shadra site. This includes different methodologies to determine the feasibility of recovery project. The laboratory results show that the percentage by volume of methane is 51%. The landfill gas (LFG generation is very low (i.e. low-range recovery scenario and it is un-economical to recover such low flow gases produced in landfill. So, this reveals that flaring is only the option to reduce the global warming potential (GWP and also the problems of odour in the vicinity of landfill.

  20. Gaseous methyl- and inorganic mercury in landfill gas from landfills in Florida, Minnesota, Delaware, and California

    Science.gov (United States)

    Lindberg, S. E.; Southworth, G.; Prestbo, E. M.; Wallschläger, D.; Bogle, M. A.; Price, J.

    2005-01-01

    Municipal waste landfills contain numerous sources of mercury which could be emitted to the atmosphere. Their generation of methane by anaerobic bacteria suggests that landfills may act as bioreactors for methylated mercury compounds. Since our previous study at a single Florida landfill, gaseous inorganic and methylated mercury species have now been identified and quantified in landfill gas at nine additional municipal landfills in several regions of the US. Total gaseous mercury occurs at concentrations in the μg m-3 range, while methylated compounds occur at concentrations in the ng m-3 range at all but one of the landfill sites. Dimethylmercury is the predominant methylated species, at concentrations up to 100 ng m-3, while monomethyl mercury was generally lower. Limited measurements near sites where waste is exposed for processing (e.g. working face, transfer areas) suggest that dimethylmercury is released during these activities as well. Although increasing amounts of landfill gas generated in the US are flared (which should thermally decompose the organic mercury to inorganic mercury), unflared landfill gas is a potentially important anthropogenic source of methylated mercury emissions to the atmosphere.

  1. Impact assessment of concentrate recirculation on the landfill gas production

    Directory of Open Access Journals (Sweden)

    Džolev Nikola M.

    2016-01-01

    Full Text Available This paper explores the impact of concentrate recirculation, as a product of leachate treated by reverse osmosis plant, on the production of landfill gas at the real-scale landfill for municipal solid waste. In an effort to come up with results experimental measurements were carried out at the landfill in Bijeljina. All measurements performed, were divided into 3 groups. The aims of two groups of measurement were to determine landfill gas and methane yield from concentrate and leachate in laboratory conditions (1st group and to find out concentrations of oxidizing matters (COD and BOD5 present in leachate and concentrate at different points of treatment as well as its variability over the time (2nd group which could be used to calculate the potential of landfill gas and methane generation from concentrate by recirculation, theoretically. 3rd group of measurements, carried out in parallel, have goal to determine the quality and quantity of the collected landfill gas at wells throughout the landfill. The results of analysis carried out in this experimental research show the clear evidence of concentrate recirculation impact on methane production by increasing the landfill gas flow, as well as its concentration within the landfill gas composition, at the nearby well. Although results indicated relatively high impact of concentrate recirculation on landfill gas production, comparing to its theoretical potential, the influence on the landfill at whole, is negligible, due to relatively low volumes in recirculation with respect to its size and objectively low potential given by organic matter present in concentrate.

  2. Generating CO(2)-credits through landfill in situ aeration.

    Science.gov (United States)

    Ritzkowski, M; Stegmann, R

    2010-04-01

    Landfills are some of the major anthropogenic sources of methane emissions worldwide. The installation and operation of gas extraction systems for many landfills in Europe and the US, often including technical installations for energy recovery, significantly reduced these emissions during the last decades. Residual landfill gas, however, is still continuously produced after the energy recovery became economically unattractive, thus resulting in ongoing methane emissions for many years. By landfill in situ aeration these methane emissions can be widely avoided both, during the aeration process as well as in the subsequent aftercare period. Based on model calculations and online monitoring data the amount of avoided CO(2-eq). can be determined. For an in situ aerated landfill in northern Germany, acting as a case study, 83-95% (depending on the kind and quality of top cover) of the greenhouse gas emission potential could be reduced under strictly controlled conditions. Recently the United Nations Framework Convention on Climate Change (UNFCCC) has approved a new methodology on the "Avoidance of landfill gas emissions by in situ aeration of landfills" (UNFCCC, 2009). Based on this methodology landfill aeration projects might be considered for generation of Certified Emission Reductions (CERs) in the course of CDM projects. This paper contributes towards an evaluation of the potential of landfill aeration for methane emissions reduction. Copyright 2009 Elsevier Ltd. All rights reserved.

  3. Comparison Of Four Landfill Gas Models Using Data From Four Danish Landfills

    DEFF Research Database (Denmark)

    Mønster, Jacob G.; Mou, Zishen; Kjeldsen, Peter

    2011-01-01

    , and to compare the four Danish landfill sites. The results show that three of the models generally give similar methane generation output. Only the LandGem model seems to give a much higher methane generation for Danish waste data, most likely due to a low organic fraction. Interpretation of the waste data......Data about type and quantity of waste disposed in four Danish landfills was collected and used on four different landfill gas generation models. This was done to compare the output data in order to evaluate the performance of the four landfill gas models when used on Danish waste types...... and the categorization of the waste play an important role in the methane prediction and combining the model predictions with whole site methane measurements would therefore be advised....

  4. Landfill gas as vehicle fuel; Deponigas som fordonsbraensle

    Energy Technology Data Exchange (ETDEWEB)

    Benjaminsson, Johan; Johansson, Nina; Karlsvaerd, Johan (Grontmij AB, Stockholm (Sweden))

    2010-03-15

    The landfill gas extraction in Sweden 2008 was 370 GWh. Mainly because of lack of available technologies for landfill gas upgrading and high assessed upgrading costs, landfill gas has so far only been used for heating and cogenerations plants (CHP). In recent years, interest has been brought to upgrade landfill gas and this study highlights the possibility of using landfill gas as fuel for vehicles. A decision in investment in an upgrading installation requires a forecast of future gas production and landfill gas extraction. From 2005, dispose of organic waste is prohibited, reducing the number of active landfills and the landfill gas production will go down. Factors such as moisture content, design of the final coverage and landfill gas collection system have a major impact on the extraction. It is therefore difficult to make appropriate predictions of the future gas production. Today's landfill gas extraction is approximately 35% of the landfill gas production and in the light of this, extraction can be in a level comparable to today's at least ten years ahead, provided that the extraction system is being expanded and that measurements are taken to so that landfills should not dry out. In comparison with biogas from anaerobic digestion in a dedicated digester, landfill gas has a high percentage of nitrogen and a content of many contaminants such as organic silicon compounds (siloxanes) and halogenated hydrocarbons (hydrocarbons containing the halogens chlorine, fluorine and bromine). This often requires more treatment and a further separation step. A common method for purification of landfill gas is regenerative adsorption on a dedicated adsorption material. Carbon dioxide is separated by conventional techniques like PSA, water scrubber and membranes. The main barrier to use landfill gas as vehicle fuel is a cost-effective separation of nitrogen that does not generate high methane losses. Nitrogen is separated by PSA or distillation technique (cryogenic

  5. Evaluation Of Landfill Gas Decay Constant For Municipal Solid Waste Landfills Operated As Bioreactors

    Science.gov (United States)

    Prediction of the rate of gas production from bioreactor landfills is important to optimize energy recovery and to estimate greenhouse gas emissions. Landfill gas (LFG) composition and flow rate were monitored for four years for a conventional and two bioreactor landfill landfil...

  6. LANDFILL GAS PRETREATMENT FOR FUEL CELL APPLICATIONS

    Science.gov (United States)

    The paper discusses the U.S. EPA's program, underway at International Fuel Cells Corporation, to demonstrate landfill methane control and the fuel cell energy recovery concept. In this program, two critical issues are being addressed: (1) a landfill gas cleanup method that would ...

  7. The Measurement of Landfill Gas Emissions with the Orbiting Carbon Observatory and CarbonSAT Satellites

    Science.gov (United States)

    Vigil, S. A.; Bovensmann, H.

    2010-12-01

    Landfill gas is a significant contributor to anthropogenic emissions of CH4 and CO2. The U.S. Environmental Protection Agency has estimated the total U.S. 2007 emissions of the CH4 component of landfill gas at 132.9 Tg CO2 Equivalent. This compares to total CH4 emission from all US sources in 2007 at 585.3 Tg CO2 Equivalent. Worldwide CH4 emissions from landfill gas have been estimated at 668 Tg CO2 Equivalent. Satellite remote sensing can also be used to characterize landfill gas emissions. The NASA Orbiting Carbon Observatory (OCO-2) and the proposed CarbonSAT (University of Bremen) satellites are particularly suited for this purpose. The Orbiting Carbon Observatory (OCO) was designed to provided high spatial resolution ( developed countries. In general, landfills in the developed countries have landfill gas control system ground based landfill gas monitoring systems. These ground-based measurements can be used to calibrate OCO-2 and CarbonSAT landfill gas measurements. OCO-2 and CarbonSAT can be used to measure landfill emissions from the large landfills and open dumps of the emerging megacities in the developing world where accurate ground measurements are not available. For example Mexico City generates 26,000 MT of municipal solid waste that is disposed of in two uncontrolled landfills. Similar conditions exist in Asia, Latin America, and Africa. Satellite based measurements of these landfill gas emissions could help prioritize greenhouse gas remediation projects for these countries.

  8. Operating a fuel cell using landfill gas

    Energy Technology Data Exchange (ETDEWEB)

    Trippel, C.E.; Preston, J.L. Jr.; Trocciola, J.; Spiegel, R.

    1996-12-31

    An ONSI PC25{trademark}, 200 kW (nominal capacity) phosphoric acid fuel cell operating on landfill gas is installed at the Town of Groton Flanders Road landfill in Groton, Connecticut. This joint project by the Connecticut Light & Power Company (CL&P) which is an operating company of Northeast Utilities, the Town of Groton, International Fuel Cells (IFC), and the US EPA is intended to demonstrate the viability of installing, operating and maintaining a fuel cell operating on landfill gas at a landfill site. The goals of the project are to evaluate the fuel cell and gas pretreatment unit operation, test modifications to simplify the GPU design and demonstrate reliability of the entire system.

  9. Gas Production Potential in the Landfill of Tehran by Landfill Methane Outreach Program

    Directory of Open Access Journals (Sweden)

    Pazoki

    2015-10-01

    Full Text Available Background Landfilling is the most common way of municipal solid waste (MSW disposal in Iran. Many countries have targeted landfill methane recovery among greenhouse gas mitigation strategies, since methane is the second most important greenhouse gas after carbon dioxide. Major questions remain with respect to actual methane production rates in field settings as well as the relative mass of methane that is recovered, emitted, oxidized by methanotrophic bacteria, laterally migrated, or temporarily stored within the landfill volume. Landfill gas (LFG consists of 50% - 60 vol% methane and 30% - 40 vol% carbon dioxide as well as trace amounts of numerous chemical compounds such as aromatics, chlorinated organic compounds and sulfur compounds. Landfill methane outreach program (LMOP is a voluntary assistance program which helps reduce methane emissions from landfills by encouraging the recovery and the beneficial use of LFG as an energy resource. Objectives In this study, the volume of LFG of Tehran by landfill methane outreach program (LMOP software was calculated. In addition, the relationship between the time of gas collection system operation and the volume of LFG production was evaluated. Materials and Methods The LMOP software was used. The available information and some presumptions were used to operate the software. The composition of the solid waste collected from the landfill of Tehran had specific details. A large amount of it was organic materials, which was about 67.8%. These materials have a good potential to produce gas. In addition, LMOP Colombia model uses the first-order equations in all the analytical equations. Furthermore, it is assumed that the landfill operation time is 30 years and the process is considered in two conditions; first, the gas was recovered in 2000, and second, the process started in 2015. Results The modeling results showed that for the gas recovery starting in 2000 and 2015, the power generation would be 2

  10. Engineering geology of landfill gas migration

    Energy Technology Data Exchange (ETDEWEB)

    Tingley, A.C.

    1990-01-01

    This thesis is divided into five chapters: Part one is an introduction to landfill gas, and why it is considered to be a problem. The subject of the migration of the gas is taken further with an examination of the state of art with respect to theories of gas transport mechanisms. A description of work which has previously been carried out upon real soils and landfill sites is included. In part two the technique developed in this research to enable a laboratory examination of real soils is discussed. Experiments are then described which form part of the landfill gas monitoring programme in the field. The whole group of data, collected at a variety of sites, included measurements of meteorological conditions, ground pressures on and off the landfill, and ground gas concentrations. The observations were used to construct a model of ground gas interchange between the landfill and surrounding land. Field pumping trials have been used to confirm these findings. The third part of the thesis is an examination of case histories, presented in order of detail available for each; results of a survey carried out between other county councils in England, and then the results of a survey in the county of Kent. Finally there is a presentation of the detailed histories of the waste disposal sites which have been examined for the purposes of this research. (Author).

  11. Modelling of landfill gas adsorption with bottom ash for utilization of renewable energy

    Energy Technology Data Exchange (ETDEWEB)

    Miao, Chen

    2011-10-06

    Energy crisis, environment pollution and climate change are the serious challenges to people worldwide. In the 21st century, human being is trend to research new technology of renewable energy, so as to slow down global warming and develop society in an environmentally sustainable method. Landfill gas, produced by biodegradable municipal solid waste in landfill, is a renewable energy source. In this work, landfill gas utilization for energy generation is introduced. Landfill gas is able to produce hydrogen by steam reforming reactions. There is a steam reformer equipment in the fuel cells system. A sewage plant of Cologne in Germany has run the Phosphoric Acid Fuel Cells power station with biogas for more than 50,000 hours successfully. Landfill gas thus may be used as fuel for electricity generation via fuel cells system. For the purpose of explaining the possibility of landfill gas utilization via fuel cells, the thermodynamics of landfill gas steam reforming are discussed by simulations. In practice, the methane-riched gas can be obtained by landfill gas purification and upgrading. This work investigate a new method for upgrading-landfill gas adsorption with bottom ash experimentally. Bottom ash is a by-product of municipal solid waste incineration, some of its physical and chemical properties are analysed in this work. The landfill gas adsorption experimental data show bottom ash can be used as a potential adsorbent for landfill gas adsorption to remove CO{sub 2}. In addition, the alkalinity of bottom ash eluate can be reduced in these adsorption processes. Therefore, the interactions between landfill gas and bottom ash can be explained by series reactions accordingly. Furthermore, a conceptual model involving landfill gas adsorption with bottom ash is developed. In this thesis, the parameters of landfill gas adsorption equilibrium equations can be obtained by fitting experimental data. On the other hand, these functions can be deduced with theoretical approach

  12. FUEL CELL ENERGY RECOVERY FROM LANDFILL GAS

    Science.gov (United States)

    International Fuel Cells Corporation is conducting a US Environmental Protection Agency (EPA) sponsored program to demonstrate energy recovery from landfill gas using a commercial phosphoric acid fuel cell power plant. The US EPA is interested in fuel cells for this application b...

  13. Comparison of green-house gas emission reductions and landfill gas utilization between a landfill system and an incineration system.

    Science.gov (United States)

    Haibin Han; Jisheng Long; Shude Li; Guangren Qian

    2010-04-01

    Electricity generation and greenhouse gas (GHG) reductions were researched by making comparisons between municipal solid waste (MSW) landfill and incineration systems with three different electricity generation efficiencies - 10%, 21%, and 24.7%. For MSW landfill systems, it is shown that the total electricity generation is 198,747 MWh, and the total GHG emission reduction is 1,386,081 tonne CO( 2) during a 21-year operation period. For incineration systems, the total electricity generation is 611,801 MWh, and the total GHG emission reduction is 1,339,158 tonne CO(2) during a 10-year operation period even if the electricity generation efficiency is only 10%. It is also shown that electricity generation increases quicker than the GHG emission reductions with the increase of electricity generation efficiency. However, incineration systems show great superiority in LFG utilisation and GHG emission reductions.

  14. Analysis of a landfill gas to energy system at the municipal solid waste landfill in Gaziantep, Turkey.

    Science.gov (United States)

    Tercan, Safak Hengirmen; Cabalar, Ali Firat; Yaman, Gokhan

    2015-08-01

    This paper presents an analysis of the electricity generation from municipal solid waste (MSW), via landfill gas valorization technology, at the landfill of Gaziantep City, Turkey. Rapid increase in population, and industrial developments, throughout the world including Turkey results in larger amount of waste materials generated, increased need for energy, and adverse affects on the environment and human health. Turkey plans to produce 1/3 of its electricity demand using renewable energy sources by the year of 2023. It is recommended to use each year around 25 million tonnes of the MSW generated nationwide for a renewable energy supply. In this study, a concise summary of current status of electricity generation from a MSW landfill gas plant (via biogas harnessing) located in Gaziantep City was analyzed as a case study.

  15. Suggested guidelines for gas emission monitoring at danish landfills

    DEFF Research Database (Denmark)

    Kjeldsen, Peter; Scheutz, Charlotte

    2015-01-01

    Landfill gas is produced on waste disposal sites receiving organic waste resulting in emission of methane. Regulation requires that the landfill gas is managed in order to reduce emissions, but very few suggestions exist to how the landfill gas management activities are monitored, what requirements...... measures to determine the efficiency of the performed emission mitigation is defined. Finally, several principles are presented for how criteria can be developed for when a monitoring program can be terminated....

  16. Optimizing gas extraction at landfills in Denmark; Optimering af gasindvinding pae deponeringsanlaeg i Danmark

    Energy Technology Data Exchange (ETDEWEB)

    Willumsen, H.C. [LFG Consult (Denmark)

    2005-07-01

    In landfills which contain organic material and anaerobic decomposition takes place, and landfill gas (LFG) is produced. The LFG contains approximately 50% methane, which contributes to the greenhouse effect when emitting from the landfill. Approximately 19% of the greenhouse gases in the atmosphere are methane, and around 8% of this is emission from landfills. This means that roughly 1.5% of the global warming is related to emission from landfills. Extraction of LFG for energy purposes was started 30 years ago in USA. In Denmark 26 LFG plants have been established since 1985. The gas is utilized for CHP or pure power production in gas engine/generator units. In some cases the LFG is used in gas burners in connection with boilers for district heating systems. 24 million m{sup 3} was recovered in 2004, which is equivalent to a reduction of CO{sub 2} of 160.000 tons CO{sub 2}/year. (BA)

  17. Feasibility study: utilization of landfill gas for a vehicle fuel system, Rossman's landfill, Clackamas County, Oregon

    Energy Technology Data Exchange (ETDEWEB)

    None

    1981-01-01

    In 1978, a landfill operator in Oregon became interested in the technical and economic feasibility of recovering the methane generated in the landfill for the refueling of vehicles. DOE awarded a grant for a site-specific feasibility study of this concept. This study investigated the expected methane yield and the development of a conceptual gas-gathering system; gas processing, compressing, and storage systems; and methane-fueled vehicle systems. Cost estimates were made for each area of study. The results of the study are presented. Reasoning that gasoline prices will continue to rise and that approximately 18,000 vehicles in the US have been converted to operate on methane, a project is proposed to use this landfill as a demonstration site to produce and process methane and to fuel a fleet (50 to 400) vehicles with the gas produced in order to obtain performance and economic data on the systems used from gas collection through vehicle operation. (LCL)

  18. Feasibility of landfill gas as a liquefied natural gas fuel source for refuse trucks.

    Science.gov (United States)

    Zietsman, Josias; Bari, Muhammad Ehsanul; Rand, Aaron J; Gokhale, Bhushan; Lord, Dominique; Kumar, Sunil

    2008-05-01

    The purpose of this paper is to develop a methodology to evaluate the feasibility of using landfill gas (LFG) as a liquefied natural gas (LNG) fuel source for heavy-duty refuse trucks operating on landfills. Using LFG as a vehicle fuel can make the landfills more self-sustaining, reduce their dependence on fossil fuels, and reduce emissions and greenhouse gases. Acrion Technologies Inc. in association with Mack Trucks Inc. developed a technology to generate LNG from LFG using the CO2 WASH process. A successful application of this process was performed at the Eco Complex in Burlington County, PA. During this application two LNG refuse trucks were operated for 600 hr each using LNG produced from gases from the landfill. The methodology developed in this paper can evaluate the feasibility of three LFG options: doing nothing, electricity generation, and producing LNG to fuel refuse trucks. The methodology involved the modeling of several components: LFG generation, energy recovery processes, fleet operations, economic feasibility, and decision-making. The economic feasibility considers factors such as capital, maintenance, operational, and fuel costs, emissions and tax benefits, and the sale of products such as surplus LNG and food-grade carbon dioxide (CO2). Texas was used as a case study. The 96 landfills in Texas were prioritized and 17 landfills were identified that showed potential for converting LFG to LNG for use as a refuse truck fuel. The methodology was applied to a pilot landfill in El Paso, TX. The analysis showed that converting LFG to LNG to fuel refuse trucks proved to be the most feasible option and that the methodology can be applied for any landfill that considers this option.

  19. Case study: City of Industry landfill gas recovery operation

    Energy Technology Data Exchange (ETDEWEB)

    None

    1981-11-01

    Development of civic, recreation, and conservation facilities throughout a 150-acre site which had been used for waste disposal from 1951 to 1970 is described. The history of the landfill site, the geology of the site, and a test well program to assess the feasibility of recoverying landfill gas economically from the site are discussed. Based on results of the test well program, the City of Industry authorized the design and installation of a full-scale landfill gas recovery system. Design, construction, and operation of the system are described. The landfill gas system provides fuel for use in boilers to meet space heating and hot water demands for site development (MCW)

  20. Tapping Landfill Gas to Provide Significant Energy Savings and Greenhouse Gas Reductions - Case Study

    Energy Technology Data Exchange (ETDEWEB)

    None

    2013-04-30

    BroadRock Renewables, LLC built two high efficiency electricity generating facilities that utilize landfill gas in California and Rhode Island. The two projects received a total of $25 million in U.S. Department of Energy funding from the American Recovery and Reinvestment Act (ARRA) of 2009. Private-sector cost share for the projects totaled approximately $186 million.

  1. Co-generation potentials of municipal solid waste landfills in Serbia

    Directory of Open Access Journals (Sweden)

    Bošković Goran B.

    2016-01-01

    Full Text Available Waste management in the Republic of Serbia is based on landfilling. As a result of such year-long practice, a huge number of municipal waste landfills has been created where landfill gas has been generated. Landfill gas, which is essentially methane (50-55% and carbon dioxide (40-45% (both GHGs, has a great environmental impact which can be reduced by using landfill gas in cogeneration plants to produce energy. The aim of this paper is to determine economic and environmental benefits from such energy production. For that purpose, the database of cogeneration potentials (CP of 51 landfills in the Republic of Serbia (RS was created. Amount of landfill gas generated at each municipal landfill was calculated by applying a first order decay equation which requires the data about solid waste production and composition and about some landfill characteristics. For all landfills, which have over 100,000 m3 each, a techno-economic analysis about building a CHP plant was conducted. The results have shown, that the total investment in 14 CHP plants with payback period of less than 7 years amounts € 11,721,288. The total nominal power of these plants is 7 MW of electrical power and 7.9 MW of thermal power, and an average payback period is about 61 months. In addition, using landfill biogas as energy source in proposed plants would reduce methane emission for 161,000 tons of CO2 equivalent per year. [Projekat Ministarstva nauke Republike Srbije, br. III 42013: Research of cogeneration potential of municipal and industrial energy power plant in Republic of Serbia and opportunities for rehabilitation of existing and construction of new cogeneration plants

  2. Designing systems for landfill gas migration control in Minnesota

    Energy Technology Data Exchange (ETDEWEB)

    Cannon, J. [Camp, Dresser & McKee, Inc., St. Paul, MN (United States)

    1996-11-01

    Camp, Dresser & McKee (CDM) has designed or is in the process of designing several landfill gas migration control systems in Minnesota. The systems are for both active and closed municipal solid waste landfills. The sites have a variety of covers, including geomembranes, clay caps, and non-engineered soil covers. The control system types include small perimeter systems, full-site systems and phased systems for active sites. Figure 1 shows the locations of the systems CDM is working on in Minnesota. This paper focuses on four sites: Oak Grove Landfill, Hopkins Landfill, Washington County Landfill, and Elk River Landfill. Table 1 provides an outline of the individual site characteristics. The first three sites are closed landfills. The Oak Grove Landfill system was designed and constructed for a group of industries responsible for closure and remedial action. The Hopkins and Washington County landfills are under the control of the Minnesota Pollution Control Agency (MPCA). The MPCA enacted a remedial action program at closed landfills, taking over responsibility for long-term liability under the terms of legally binding agreements negotiated with the site owners. The Elk River Landfill is an active, privately-owned facility. The migration problems and solutions developed for these four landfills are generally descriptive of all the landfills CDM is working on in Minnesota. All landfills have unique characteristics requiring site-specific solutions. CDM, after designing a number of migration control systems in Minnesota, is able to provide a generalized description of design options for specific types of sites. This paper discussions design options used to address different cover types, aesthetic needs, and waste depths, and includes a discussion of design needs for cold climates. A brief case history of the Oak Grove Landfill is included.

  3. Danish landfill gas plants with automatic measuring and regulation system

    Energy Technology Data Exchange (ETDEWEB)

    Willumsen, H. [Danish Land Development Service (Denmark)

    1996-12-31

    The first landfill gas plants in the USA were established on large and deep landfills. A number of wells were made and connected to a horizontal suction pipe through which the gas was sucked from the landfill. Most of the gas extraction systems are still constructed that way. However, control and optimising of the gas extraction can be problematic when a great number of drillings are connected to the same suction pipe. Since 1981 the Danish Ministry of Energy has supported selected research and development projects in connection with extraction and utilisation of landfill gas from Danish landfills, including a pilot plant implemented in 1983. In 1985 a EU-financed demonstration plant was established in Viborg, Denmark. In connection with the pilot and EU demonstration plant an automatic measuring and regulation system was developed to secure optimal gas recovery, identical gas quality and furthermore, it has the advantage of remote monitoring and regulation which save operational costs. The automatic measuring and regulation system is in particular well-suited when the landfill is of a relatively low depth and where regulation of the extraction may cause problems embodied in atmospheric air being sucked down in the landfill causing fluctuation of the gas quality and consequently of the gas quantity. (Author)

  4. Observations from using models to fit the gas production of varying volume test cells and landfills.

    Science.gov (United States)

    Lamborn, Julia

    2012-12-01

    Landfill operators are looking for more accurate models to predict waste degradation and landfill gas production. The simple microbial growth and decay models, whilst being easy to use, have been shown to be inaccurate. Many of the newer and more complex (component) models are highly parameter hungry and many of the required parameters have not been collected or measured at full-scale landfills. This paper compares the results of using different models (LANDGEM, HBM, and two Monod models developed by the author) to fit the gas production of laboratory scale, field test cell and full-scale landfills and discusses some observations that can be made regarding the scalability of gas generation rates. The comparison of these results show that the fast degradation rate that occurs at laboratory scale is not replicated at field-test cell and full-scale landfills. At small scale, all the models predict a slower rate of gas generation than actually occurs. At field test cell and full-scale a number of models predict a faster gas generation than actually occurs. Areas for future work have been identified, which include investigations into the capture efficiency of gas extraction systems and into the parameter sensitivity and identification of the critical parameters for field-test cell and full-scale landfill predication.

  5. Albany Interim Landfill gas extraction and mobile power system: Using landfill gas to produce electricity. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-06-01

    The Albany Interim Landfill Gas Extraction and Mobile Power System project served three research objectives: (1) determination of the general efficiency and radius of influence of horizontally placed landfill gas extraction conduits; (2) determination of cost and effectiveness of a hydrogen sulfide gas scrubber utilizing Enviro-Scrub{trademark} liquid reagent; and (3) construction and evaluation of a dual-fuel (landfill gas/diesel) 100 kW mobile power station. The horizontal gas extraction system was very successful; overall, gas recovery was high and the practical radius of influence of individual extractors was about 50 feet. The hydrogen sulfide scrubber was effective and its use appears feasible at typical hydrogen sulfide concentrations and gas flows. The dual-fuel mobile power station performed dependably and was able to deliver smooth power output under varying load and landfill gas fuel conditions.

  6. Measurement of representative landfill gas migration samples at landfill perimeters: a case study

    OpenAIRE

    Kiernan, Breda M.; Beirne, Stephen; Fay, Cormac; Diamond, Dermot

    2009-01-01

    This paper describes the development of a fully integrated autonomous system based on existing infrared sensing technology capable of monitoring landfill gas migration (specifically carbon dioxide and methane) at landfill sites. Sampling using the described system was validated against the industry standard, GA2000 Plus hand held device, manufactured by Geotechnical Instruments Inc. As a consequence of repeated sampling during validation experiments, fluctuations in the gas mixtures became ap...

  7. Evolution on qualities of leachate and landfill gas in the semi-aerobic landfill

    Institute of Scientific and Technical Information of China (English)

    HUANG Qifei; YANG Yufei; PANG Xiangrui; WANG Qi

    2008-01-01

    To study the characteristics of stabilization in semi-aerobic landfill, large-scale simulated landfill was constructed based on the semi-aerobic landfill theory. Consequently, the concentrations of chemical oxygen demand (COD), ammonia nitrogen, and nitrite nitrogen, and the pH value in leachate, as well as the component contents of landfill gas composition (methane, carbon dioxide, and oxygen) in landfill were regularly monitored for 52 weeks. The results showed that COD and ammonia concentrations declined rapidly and did not show the accumulating rule like anaerobic landfill, and remained at about 300 and 100 mg/L, respectively, after 48 weeks. Meanwhile, the descending rate reached 98.9% and 96.9%, respectively. Nitrate concentration increased rapidly after 24 weeks and fluctuated between 220-280 mg/L after 43 weeks. The pH values were below 7 during the first 8 weeks and after that leachates appeared to be alkaline. Carbon dioxide was the main composition in landfill gas and its concentration remained at a high level through the whole stabilization process. The average contents of carbon dioxide, oxygen, and methane varied between 19 vol.%-28 vol.%, 2 vol.%-8 vol.%, and 5 vol.%-13 vol.%, respectively. A relative equilibrium was reached after 48 weeks. The highest temperature in the landfill chamber could amount to 75.8 degrees centigrade.

  8. Recovery of landfill gas. Udnyttelse af lossepladsgas; Demonstrationsprojekt: Endelige rapporter

    Energy Technology Data Exchange (ETDEWEB)

    Willumsen, H.C. (Novo Industri A/S, Bagsvaerd (Denmark))

    1989-01-01

    The present report treats of the establishment of a demonstration plant for exploitation of landfill gas, the experience that has been gleaned and the results achieved in this connection. The main objective of the project was to construct a plant which can ensure optimum recovery and exploitation of the landfill gas in small landfills where the filling height is relatively low. Also, the plant should be economically viable. For optimum recovery a special adjustment system was introduced, which has proved very satisfactory, as it has resulted in an increase in the recovered gas volume and ensures a constant methane content. The landfill gas is used in a boiler which supplies heat to Viborg district heating system. Some of the gas is used in a Stirling motor in order to test how this particular motor works on landfill gas. The report contains information about the measuring and registration system of the plant and data derived from the measuring programme. The project has been implemented by Crone Koch in a close cooperation with the owner of the landfill, Viborg Municipality, and the main contractor, A/S Marius Pedersen. The demonstration project has been granted financial support by the Commission of the EEC (Contract no. BM741/83, Recovery of Landfill Gas''), and by the Danish Ministry of Energy. 42 figs., 6 tabs.

  9. Investigation of Integrated Subsurface Processing of Landfill Gas and Carbon Sequestration, Johnson County, Kansas

    Energy Technology Data Exchange (ETDEWEB)

    K. David Newell; Timothy R. Carr

    2007-03-31

    The Johnson County Landfill in Shawnee, KS is operated by Deffenbaugh Industries and serves much of metropolitan Kansas City. Refuse, which is dumped in large plastic-underlined trash cells covering several acres, is covered over with shale shortly after burial. The landfill waste, once it fills the cell, is then drilled by Kansas City LFG, so that the gas generated by anaerobic decomposition of the refuse can be harvested. Production of raw landfill gas from the Johnson County landfill comes from 150 wells. Daily production is approximately 2.2 to 2.5 mmcf, of which approximately 50% is methane and 50% is carbon dioxide and NMVOCs (non-methane volatile organic compounds). Heating value is approximately 550 BTU/scf. A upgrading plant, utilizing an amine process, rejects the carbon dioxide and NMVOCs, and upgrades the gas to pipeline quality (i.e., nominally a heating value >950 BTU/scf). The gas is sold to a pipeline adjacent to the landfill. With coal-bearing strata underlying the landfill, and carbon dioxide a major effluent gas derived from the upgrading process, the Johnson County Landfill is potentially an ideal setting to study the feasibility of injecting the effluent gas in the coals for both enhanced coalbed methane recovery and carbon sequestration. To these ends, coals below the landfill were cored and then were analyzed for their thickness and sorbed gas content, which ranged up to 79 scf/ton. Assuming 1 1/2 square miles of land (960 acres) at the Johnson County Landfill can be utilized for coalbed and shale gas recovery, the total amount of in-place gas calculates to 946,200 mcf, or 946.2 mmcf, or 0.95 bcf (i.e., 985.6 mcf/acre X 960 acres). Assuming that carbon dioxide can be imbibed by the coals and shales on a 2:1 ratio compared to the gas that was originally present, then 1682 to 1720 days (4.6 to 4.7 years) of landfill carbon dioxide production can be sequestered by the coals and shales immediately under the landfill. Three coal--the Bevier

  10. Assessing Emissions of Volatile Organic Componds from Landfills Gas

    Directory of Open Access Journals (Sweden)

    Fahime Khademi

    2016-01-01

    Full Text Available Background: Biogas is obtained by anaerobic decomposition of organic wastes buried materials used to produce electricity, heat and biofuels. Biogas is at the second place for power generation after hydropower and in 2000 about 6% of the world power generation was allocated to biogas. Biogas is composed of 40–45 vol% CO2, 55–65 vol% CH4, and about 1% non-methaneVOCs, and non-methane volatile organic compounds. Emission rates are used to evaluate the compliance with landfill gas emission regulations by the United States Environmental Protection Agency (USEPA. BTEX comounds affect the air quality and may be harmful to human health. Benzene, toluene, ethylbenzene and xylene isomers that are generally called BTEX compounds are the most abundant VOCs in biogas. Methods: Sampling of VOCs in biogas vents was operated passively or with Tedlar bags. 20 samples were collected from 40 wells of old and new biogas sites of Shiraz’ landfill. Immediately after sampling, the samples were transferred to the laboratory. Analysis of the samples was performed with GC-MS. Results: The results showed that in the collection of the old and new biogas sites, the highest concentration of VOCs was observed in toluene (0.85ppm followed by benzene (0.81ppm, ethylbenzene (0.13ppm and xylene (0.08ppm. Conclusion: The results of the study showed that in all samples, most available compounds in biogas vents were aromatic hydrocarbon compounds.These compounds’ constituents originate from household hazardous waste materials deposited in the landfill or from biological/chemical decomposition processes within the landfill.

  11. Exergetic analysis of a power plant using landfill gas

    Energy Technology Data Exchange (ETDEWEB)

    Mert, Mehmet Selcuk [Yalova University, Energy Systems Engineering Department (Turkey)], email: msmert@yalova.edu.tr; Dilmac, Omer Faruk; Ozkan, Semra; Bolat, Esen [Yildiz Technical University Chemical Engineering Department (Turkey)], email: omerfarukdl@yahoo.com, email: ozkans@yildiz.edu.tr, email: ebolat@yildiz.edu.tr; Mert, Hatice Hande [Yalova University, Chemical and Process Engineering Department (Turkey)], email: hndmert@yalova.edu.tr

    2011-07-01

    Landfill gas production results from chemical reactions and anaerobic decomposition of biodegradable organic materials at the municipal waste facility as the putrescible materials begin to break down in the landfill. Using landfill gas in internal combustion engines to produce electricity helps in reducing emissions, protecting the environment and saving energy resources. In order to determine the real thermodynamic efficiency of the system and its components, an exergetic analysis of a power plant using landfill gas as fuel was studied in this article. The mass, energy, and exergy balances were done for each piece of equipment and, based on these parameters, exergy destructions and the improvement potential with respect to the landfill gas compressor and gas engine were determined. The results show that the total exergy destruction was 2305.54 kW, the exergy efficiencies were 85.83% and 40.50%, and the energy efficiencies were 94.40% and 45.61% for the landfill gas compressor and gas engine, respectively.

  12. Potential for electric power generation and gas lighting through the use of biogas from landfill; Potencial de geracao de energia eletrica e iluminacao a gas por meio do aproveitamento de biogas proveniente de aterro sanitario

    Energy Technology Data Exchange (ETDEWEB)

    Pecora, V.; Figueiredo, N.J.V.; Coelho, S.T. [Universidade de Sao Paulo (CENBIO/USP), SP (Brazil). Inst. de Eletrotecnica e Energia. Centro Nacional de Referencia em Biomassa; Velazquez, S.M.S.G. [Universidade Presbiteriana Mackenzie, Sao Paulo, SP (Brazil). Dept. de Engenharia Mecanica

    2008-07-01

    Global warming has become an important topic of global discussions due to the increasing concentration of greenhouse gases in the atmosphere, coming mainly on the burning of fossil fuels. The search for alternatives that promote the replacement of these fuels by renewable sources has been intensified in recent decades and several studies are being undertaken to ensure, for example, the efficient management and minimization of solid waste, seen as a serious problem of large Brazilians urban centers nowadays. The incorrect final disposal of solid waste entails in uncontrolled emission of gases, generated in its decomposition, and the infiltration of percolated liquid in the soil; resulting on negative impacts on people's health and on the environment, also contributing to the worsening of the greenhouse effect. In this context, this article presents the project of exploitation of biogas from the treatment of urban solid waste for generating electric power and gas lighting, developed by the Brazilian Reference Center on Biomass (CENBIO), at Caieiras Waste Treatment Centre (Essencis CTR - Caieiras). This paper describes the activities developed by CENBIO for determining the potential of electricity generation and gas lighting and, through the results, may be defined other landfills for implementation of a similar project. The use of biogas for energy generation provides the rational use of available sources, reducing dependence on external energy sources and, as the conversion of methane into carbon dioxide, promotes the reduction of emissions of greenhouse gases, since methane has the global warming potential about 20 times higher when compared to carbon dioxide. (author)

  13. 城市生活垃圾填埋的产气过程实验室模拟%Study on the Generation Process of Landfill Gas by Laboratory Simulation

    Institute of Scientific and Technical Information of China (English)

    刘富强; 唐薇; 聂永丰

    2001-01-01

    The laboratory simulation was adopted to study the generationprocess of landfill gas,and the characteristics of the gas production and gas composition for the typical MSW in China were discussed.Moreover,it is demonstrated that the gas generation amount can be dramatically increased by leachate recharging.%本文探讨了如何在实验室中建立比较符合填埋场实际情况的垃圾填埋模拟实验系统及实验方法;研究了我国以食品垃圾为主要成分的城市垃圾在填埋模拟系统中的产气量和气体组成的变化规律;证明了渗滤液回灌能够明显增加填埋系统的产气量。

  14. Gas breakthrough and emission through unsaturated compacted clay in landfill final cover

    Energy Technology Data Exchange (ETDEWEB)

    Ng, C.W.W.; Chen, Z.K.; Coo, J.L. [Department of Civil and Environmental Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong); Chen, R., E-mail: chenrui1005@hotmail.com [Shenzhen Key Laboratory of Urban and Civil Engineering for Disaster Prevention and Mitigation, Harbin Institute of Technology Shenzhen Graduate School, Shenzhen 518055 (China); Zhou, C. [Department of Civil and Environmental Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong)

    2015-10-15

    Highlights: • Explore feasibility of unsaturated clay as a gas barrier in landfill cover. • Gas breakthrough pressure increases with clay thickness and degree of saturation. • Gas emission rate decreases with clay thickness and degree of saturation. • A 0.6 m-thick clay layer may be sufficient to meet gas emission rate limit. - Abstract: Determination of gas transport parameters in compacted clay plays a vital role for evaluating the effectiveness of soil barriers. The gas breakthrough pressure has been widely studied for saturated swelling clay buffer commonly used in high-level radioactive waste disposal facility where the generated gas pressure is very high (in the order of MPa). However, compacted clay in landfill cover is usually unsaturated and the generated landfill gas pressure is normally low (typically less than 10 kPa). Furthermore, effects of clay thickness and degree of saturation on gas breakthrough and emission rate in the context of unsaturated landfill cover has not been quantitatively investigated in previous studies. The feasibility of using unsaturated compacted clay as gas barrier in landfill covers is thus worthwhile to be explored over a wide range of landfill gas pressures under various degrees of saturation and clay thicknesses. In this study, to evaluate the effectiveness of unsaturated compacted clay to minimize gas emission, one-dimensional soil column tests were carried out on unsaturated compacted clay to determine gas breakthrough pressures at ultimate limit state (high pressure range) and gas emission rates at serviceability limit state (low pressure range). Various degrees of saturation and thicknesses of unsaturated clay sample were considered. Moreover, numerical simulations were carried out using a coupled gas–water flow finite element program (CODE-BRIGHT) to better understand the experimental results by extending the clay thickness and varying the degree of saturation to a broader range that is typical at different

  15. The Use of Biofilter to Reduce Atmospheric Global Warming Gas (CH4) Eemissions from Landfills

    Science.gov (United States)

    Park, S.; Thomas, J. C.; Brown, K. W.; Sung, K.

    2001-12-01

    The emission of greenhouse gasses resulting from anthropogenic activities is increasing the atmospheric concentration of these gases, which can influence the climatic system by changing the temperature, precipitation, wind and other climate factors. Methane (CH4) is a very potent greenhouse gas and CH4 emission from landfills in US has been reported as 37% of total anthropogenic source of CH4 emission. Properly designed soil biofilters may reduce atmospheric CH4 emissions from landfills and help reduce the accumulation of greenhouse gasses in the atmosphere. Biofilter performance was tested under a variety of environmental and design conditions. The results showed that biofilters have the potential to reduce CH4 emissions from landfills by as much as 83%. A quadratic equation was developed to describe the dependence of methane oxidation rate in a sandy loam textured soil as a function of soil temperature, soil moisture and ammonium nitrogen concentration. Using this equation and the averaged soil temperature and moisture contents, and census data for the largest cities of each of the 48 contiguous states, oxidation rates was calculated. A methane emission model was also developed to estimate the methane emission from municipal waste landfills with different covers. Older landfills with soil covers emitted an average of 83% of the generated CH4. Landfills with RCRA covers emitted 90% of the generated CH4 without biofilters and only 10% with biofilters. Thus, the installation of properly sized biofilters should significantly reduce atmospheric CH4 emissions from landfills.

  16. Effects of landfill gas on subtropical woody plants

    Science.gov (United States)

    Chan, G. Y. S.; Wong, M. H.; Whitton, B. A.

    1991-05-01

    An account is given of the influence of landfill gas on tree growth in the field at Gin Drinkers' Bay (GDB) landfill, Hong Kong, and in the laboratory. Ten species ( Acacia confusa, Albizzia lebbek, Aporusa chinensis, Bombax malabaricum, Castanopsis fissa, Liquidambar formosana, Litsea glutinosa, Machilus breviflora, Pinus elliottii, and Tristania conferta), belonging to eight families, were transplanted to two sites, one with a high concentration of landfill gas in the cover soil (high-gas site, HGS) and the other with a relatively low concentration of gas (low-gas site, LGS). Apart from the gaseous composition, the general soil properties were similar. A strong negative correlation between tree growth and landfill gas concentration was observed. A laboratory study using the simulated landfill gas to fumigate seedlings of the above species showed that the adventitious root growth of Aporusa chinensis, Bombax malabaricum, Machilus breviflora, and Tristania confera was stimulated by the gas, with shallow root systems being induced. Acacia confusa, Albizzia lebbek, and Litsea glutinosa were gas-tolerant, while root growth of Castanopsis fissa, Liquidambar formosana, and Pinus elliottii was inhibited. In most cases, shoot growth was not affected, exceptions being Bombax malabaricum, Liquidambar formosana, and Tristania conferta, where stunted growth and/or reduced foliation was observed. A very high CO2 concentration in cover soil limits the depth of the root system. Trees with a shallow root system become very susceptible to water stress. The effects of low O2 concentration in soil are less important than the effects of high CO2 concentration. Acacia confusa, Albizzia lebbek, and Tristania conferta are suited for growth on subtropical completed landfills mainly due to their gas tolerance and/or drought tolerance.

  17. Greenhouse gas reduction by recovery and utilization of landfill methane and CO{sub 2} technical and market feasibility study, Boului Landfill, Bucharest, Romania. Final report, September 30, 1997--September 19, 1998

    Energy Technology Data Exchange (ETDEWEB)

    Cook, W.J.; Brown, W.R.; Siwajek, L. [Acrion Technologies, Inc., Cleveland, OH (United States); Sanders, W.I. [Power Management Corp., Bellevue, WA (United States); Botgros, I. [Petrodesign, SA, Bucharest (Romania)

    1998-09-01

    The project is a landfill gas to energy project rated at about 4 megawatts (electric) at startup, increasing to 8 megawatts over time. The project site is Boului Landfill, near Bucharest, Romania. The project improves regional air quality, reduces emission of greenhouse gases, controls and utilizes landfill methane, and supplies electric power to the local grid. The technical and economic feasibility of pre-treating Boului landfill gas with Acrion`s new landfill gas cleanup technology prior to combustion for power production us attractive. Acrion`s gas treatment provides several benefits to the currently structured electric generation project: (1) increase energy density of landfill gas from about 500 Btu/ft{sup 3} to about 750 Btu/ft{sup 3}; (2) remove contaminants from landfill gas to prolong engine life and reduce maintenance;; (3) recover carbon dioxide from landfill gas for Romanian markets; and (4) reduce emission of greenhouse gases methane and carbon dioxide. Greenhouse gas emissions reduction attributable to successful implementation of the landfill gas to electric project, with commercial liquid CO{sub 2} recovery, is estimated to be 53 million metric tons of CO{sub 2} equivalent of its 15 year life.

  18. Bioenergy recovery from landfill gas: A case study in China

    Institute of Scientific and Technical Information of China (English)

    Wei WANG; Yuxiang LUO; Zhou DENG

    2009-01-01

    Landfill gas (LFG) utilization which means a synergy between environmental protection and bioenergy recovery was investigated in this study. Pressure swing adsorption technology was used in LFG purification, and laboratory experiment, pilot-scale test, and on-site demon-stration were carried out in Shenzhen, China. In the laboratory experiment, A-type carbon molecular sieve was selected as the adsorbent by comparison of several other adsorbents. The oPtimal adsorption pressure and adsorp-tion time were 0.25 MPa and 2 min, respectively, under which the product generation rate was 4.5 m3/h and the methane concentration was above 90%. The process and optimization of the pilot-scale test were also reported in the paper. The product gas was of high quality compared with the National Standard of Compressed Natural Gas as Vehicle Fuel (GB 18047-2000), when the air concentration in feed gas was under 10.96%. The demonstration project was composed of a collection system, production system,and utilization system. The drive performance, environ-mental protection performance, and economic feasibility of the product gas -- as alternative fuel in passenger car,truck, and bulldozer-were tested, showing the feasibility technology for LFG utilization.

  19. Methylated mercury species in municipal waste landfill gas sampled in Florida, USA

    Science.gov (United States)

    Lindberg, S. E.; Wallschläger, D.; Prestbo, E. M.; Bloom, N. S.; Price, J.; Reinhart, D.

    Mercury-bearing material has been placed in municipal landfills from a wide array of sources including fluorescent lights, batteries, electrical switches, thermometers, and general waste. Despite its known volatility, persistence, and toxicity in the environment, the fate of mercury in landfills has not been widely studied. The nature of landfills designed to reduce waste through generation of methane by anaerobic bacteria suggests the possibility that these systems might also serve as bioreactors for the production of methylated mercury compounds. The toxicity of such species mandates the need to determine if they are emitted in municipal landfill gas (LFG). In a previous study, we had measured levels of total gaseous mercury (TGM) in LFG in the μg/m 3 range in two Florida landfills, and elevated levels of monomethyl mercury (MMM) were identified in LFG condensate, suggesting the possible existence of gaseous organic Hg compounds in LFG. In the current study, we measured TGM, Hg 0, and methylated mercury compounds directly in LFG from another Florida landfill. Again, TGM was in the μg/m 3 range, MMM was found in condensate, and this time we positively identified dimethyl mercury (DMM) in the LGF in the ng/m 3 range. These results identify landfills as a possible anthropogenic source of DMM emissions to air, and may help explain the reports of MMM in continental rainfall.

  20. LCA and economic evaluation of landfill leachate and gas technologies.

    Science.gov (United States)

    Damgaard, Anders; Manfredi, Simone; Merrild, Hanna; Stensøe, Steen; Christensen, Thomas H

    2011-07-01

    Landfills receiving a mix of waste, including organics, have developed dramatically over the last 3-4 decades; from open dumps to engineered facilities with extensive controls on leachate and gas. The conventional municipal landfill will in most climates produce a highly contaminated leachate and a significant amount of landfill gas. Leachate controls may include bottom liners and leachate collection systems as well as leachate treatment prior to discharge to surface water. Gas controls may include oxidizing top covers, gas collection systems with flares or gas utilization systems for production of electricity and heat. The importance of leachate and gas control measures in reducing the overall environmental impact from a conventional landfill was assessed by life-cycle-assessment (LCA). The direct cost for the measures were also estimated providing a basis for assessing which measures are the most cost-effective in reducing the impact from a conventional landfill. This was done by modeling landfills ranging from a simple open dump to highly engineered conventional landfills with energy recovery in form of heat or electricity. The modeling was done in the waste LCA model EASEWASTE. The results showed drastic improvements for most impact categories. Global warming went from an impact of 0.1 person equivalent (PE) for the dump to -0.05 PE for the best design. Similar improvements were found for photochemical ozone formation (0.02 PE to 0.002 PE) and stratospheric ozone formation (0.04 PE to 0.001 PE). For the toxic and spoiled groundwater impact categories the trend is not as clear. The reason for this was that the load to the environment shifted as more technologies were used. For the dump landfill the main impacts were impacts for spoiled groundwater due to lack of leachate collection, 2.3 PE down to 0.4 PE when leachate is collected. However, at the same time, leachate collection causes a slight increase in eco-toxicity and human toxicity via water (0.007 E to 0

  1. Gas Transport Parameters for Landfill Final Cover Soil: Measurements and Model Modification by Dry Bulk Density

    Science.gov (United States)

    Wickramarachchi, P. N.; Kawamoto, K.; Hamamoto, S.; Nagamori, M.; Moldrup, P.; Komatsu, T.

    2011-12-01

    Landfill sites have been emerging in greenhouse warming scenarios as a significant source of atmospheric methane (CH4). Until recently, landfill management strategies have mainly addressed the problem of preventing groundwater contamination and reduction of leachate generation. Being one of the largest sources of anthropogenic CH4 emission, the final cover system should also be designed for minimizing the greenhouse gases migration into the atmosphere or the areas surrounding the landfill while securing the hydraulic performance. Compared to the intensive research efforts on hydraulic performances of landfill final cover soil, few studies about gas transport characteristics of landfill cover soils have been done. However, recent soil-gas studies implied that the effects of soil physical properties such as bulk density (i.e., compaction level), soil particle size are key parameters to understand landfill gaseous performance. The gas exchange through the final cover soils is controlled by advective and diffusive gas transport. Air permeability (ka) governs the advective gas transport while the soil-gas diffusion coefficient (Dp) governs diffusive gas transport. In this study, the effects of compaction level and particle size fraction effects on ka and Dp for landfill final cover soil was investigated. The disturbed soil samples were taken from landfill final cover in Japan. A compaction tests were performed for the soil samples with two different size fractions (content , the soil samples were repacked into soil cores (i.d. 15-cm, length 12-cm, 2120 cm3) at two different compaction levels [(MP):2700 kN/m2 and (SP):600 kN/m2]. After the compaction tests, ka and Dp were measured and then samples were saturated and subsequently drained at different soil-water matric potential of 0.98, 2.94, 9.81, 1235 kPa and with air-dried and oven-dried conditions. Results showed that measured Dp and ka values for the coarser (content. Further, compaction effort was much significant

  2. LIQUID NATURAL GAS (LNG): AN ALTERNATIVE FUEL FROM LANDFILL GAS (LFG) AND WASTEWATER DIGESTER GAS

    Energy Technology Data Exchange (ETDEWEB)

    VANDOR,D.

    1999-03-01

    This Research and Development Subcontract sought to find economic, technical and policy links between methane recovery at landfill and wastewater treatment sites in New York and Maryland, and ways to use that methane as an alternative fuel--compressed natural gas (CNG) or liquid natural gas (LNG) -- in centrally fueled Alternative Fueled Vehicles (AFVs).

  3. Landfill gas control facility with automatic wobbe-correction for Gas-Otto-Engines

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, K.; Pauli, H.

    1986-01-01

    In open sanitary landfills large amounts of energy-rich landfillgas is generated. Without a purposeful collection, this gas would escape into the covering layers and into the air and thus burden the environment. In the sanitary landfill of 'Gummersloch' near Berne, the gas is systematically collected and piped to the Senior and Nursing Home of Kuehlewil where it is utilised in a thermal power-coupling facility (heating power station) of the Bernese Power Plants (BKW) to produce power and heat. This plant, with additional equipment for the automatic wobbe-correction, has been in operation for about 2 years and has proved its worth in practical use. By way of the automatic wobbe-correction through the disturbance-variable feed-forward system, the uncontrolled occuring fluctuations of the gas quality are being, up to 40%, so levelled out, that a faultless operation is guaranteed. Actual experiences have confirmed that the adaption to changing gas qualities by means of the constant extended wobbe-index is ideally suited to the use of gas engines.

  4. Gas exchanges in soybean as affected by landfill biogas atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Marchiol, L.; Zerbi, G. (Univ. di Udine (Italy). Dipt. di Produzione Vegetale e Tecnologie Agrarie); Mori, A.; Leita, L. (Ist. Sperimentale per la Nutrizione delle Piante-Sezione di Gorizia (Italy))

    A problem in the ecological restoration of closed landfills is the production of potentially toxic gases by decomposition of refuse that affects the root system and physiology of plants growing on these sites. The aim of the present study was to assess the effects induced by landfill biogas contamination on gas-exchanges of soybean [Glycine max (L.) Merr.]. Simulated landfill and control gases were supplied to soybean plants under laboratory conditions for 10 d. The composition of the simulated landfill gas used was: 16% O[sub 2], 8% CO[sub 2], 3% CH[sub 4], and 73% N[sub 2]; a control gas was also tested. Photosynthesis and stomatal conductance were significantly affected by the gas treatment after 3 d; in the course of the experiment, biogas treatment progressively reduced A[sub max] in light-saturation curves. The fresh and dry weight, leaf area and leaf chlorophyll content were not affected by the treatment. A metabolic adaptation to the biogas in the roots of treated plants was related to the disappearance of a fraction of the protein pool.

  5. FUEL CELL OPERATION ON LANDFILL GAS AT PENROSE POWER STATION

    Science.gov (United States)

    This demonstration test successfully demonstrated operation of a commercial phosphoric acid fuel cell (FC) on landfill gas (LG) at the Penrose Power Station in Sun Valley, CA. Demonstration output included operation up to 137 kW; 37.1% efficiency at 120 kW; exceptionally low sec...

  6. Landfills

    Data.gov (United States)

    Vermont Center for Geographic Information — This data set defines both current and historic landfills/waste disposal storage sites for the State of Vermont. Historic landfills were identified with the...

  7. Evaluating Gas Emissions From Landfills – Which Methodologies Can Be Used?

    DEFF Research Database (Denmark)

    Kjeldsen, Peter; Scheutz, Charlotte

    2011-01-01

    Many methodologies exist to measure whole landfill methane emission as alternatives to imprecise estimation of the methane emission using existing landfill gas generation models. An overview of the different measurement methodologies is given, and suggestions to the most promising methodologies...... are presented. Methods based on the tracer dilution approach are most promising. However, still some developments are needed, both in respect to the technical implementation, and in respect to the protocols needed to obtain annual emission estimates based on the limited number of measurement campaigns....

  8. Lateral gas transport in soil adjacent to an old landfill: factors governing gas migration

    DEFF Research Database (Denmark)

    Christophersen, Mette; Kjeldsen, Peter

    2001-01-01

    migration of landfill gas was a very dynamic system and the concentrations of LFG at a specific place and depth changed dramatically within a very short time. The experiments showed that change in barometric pressure was an important factor affecting gas migration at the Skellingsted landfill in Denmark.......Field experiments investigating lateral gas transport in soil adjacent to an old landfill in Denmark during a one-year period were conducted. A significant seasonal variation, with low concentrations of methane and high concentrations of carbon dioxide in the summer, caused by methane oxidation...

  9. Biogas generation in landfills. Equilibria, rates and yields

    Energy Technology Data Exchange (ETDEWEB)

    Aakesson, M.

    1997-05-01

    Landfilling in `cells` has become more common in recent years. Different waste streams are guided to different cells, among which the biocell is a landfill designed for biogas production. In this thesis, the dependence of biogas generation on waste composition was investigated. Six 8,000 m{sup 3} test cells, with contents ranging from mainly commercial waste to pure domestic waste and equipped with gas extraction systems and bottom plastic liners, were monitored for seven years. Great emphasis was given to the characterization of conversion processes and governing mechanism in the topics of bio-energetics, kinetics and capacities. A thermodynamic model, in which the oxidations of volatile fatty acids (VFA) (2

  10. Effect of nano-ZnO on biogas generation from simulated landfills.

    Science.gov (United States)

    Temizel, İlknur; Emadian, S Mehdi; Di Addario, Martina; Onay, Turgut T; Demirel, Burak; Copty, Nadim K; Karanfil, Tanju

    2017-05-01

    Extensive use of nanomaterials in commercial consumer products and industrial applications eventually leads to their release to the waste streams and the environment. Nano-ZnO is one of the most widely-used nanomaterials (NMs) due to its unique properties. It is also known to impact biological processes adversely. In this study, the effect of nano-ZnO on biogas generation from sanitary landfills was investigated. Two conventional and two bioreactor landfills were operated using real MSW samples at mesophilic temperature (35°C) for a period of about 1year. 100mg nano-ZnO/kg of dry waste was added to the simulated landfill reactors. Daily gas production, gas composition and leachate Zn concentrations were regularly monitored. A model describing the fate of the nano-ZnO was also developed. The results obtained indicated that as much as 99% of the nano-ZnO was retained within the waste matrix for both reactor operation modes. Waste stabilization was faster in simulated landfill bioreactors with and without the addition of nano-ZnO. Moreover, the presence of the nano-ZnO within the waste led to a decrease in biogas production of about 15%, suggesting that the nano-ZnO might have some inhibitory effects on waste stabilization. This reduction can have potentially significant implications on waste stabilization and the use of biogas from landfills as a renewable energy source. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Development of the utilization of combustible gas produced in existing sanitary landfills: Investigation of effects of air inclusion

    Science.gov (United States)

    1983-01-01

    The effects of nitrogen and oxygen on landfill gas operations are discussed. A combustible gas mixture composed of methane and carbon dioxide is generated in municipal solid waste landfills. A consequence of the collection of this fuel gas is the inclusion of some air in the collected product. The effects include increased collected and purification costs, reduction in the quality of the fuel gas produced, corrosion, explosion hazards, and interference with odorant systems. The scope of such effects was determined by using landfill data of a gas recovery site as a basis. Useful supplemental fuel gas may be recovered despite the inclusion of air. Recommendations are made for establishing limits for nitrogen and oxygen content and minimizing the costs associated with their presence.

  12. Estimation of emissions of nonmethane organic compounds from a closed landfill site using a landfill gas emission model

    Energy Technology Data Exchange (ETDEWEB)

    Nwachukwu, A.N. [Williamson Research Centre for Molecular Environmental Sciences, School of Earth, Atmospheric and Environmental Science, University of Manchester M13 9PL (United Kingdom); Diya, A.W. [Health Sciences Research Group, School of Medicine, University of Manchester M13 9PL (United Kingdom)

    2013-07-01

    Nonmethane organic compounds (NMOC) emissions from landfills often constitute significant risks both to human health and the general environment. To date very little work has been done on tracking the emissions of NMOC from landfills. To this end, a concerted effort was made to investigate the total annual mass emission rate of NMOC from a closed landfill site in South Manchester, United Kingdom. This was done by using field estimates of NMOC concentration and the landfill parameters into the Landfill Gas Emission Model embedded in ACTS and RISK software. Two results were obtained: (i) a deterministic outcome of 1.7218 x 10-7 kg/year, which was calculated from mean values of the field estimates of NMOC concentration and the landfill parameters, and (ii) a probabilistic outcome of 1.66 x 10-7 - 1.78 x 10-7 kg/year, which is a range of value obtained after Monte Carlo simulation of the uncertain parameters of the landfill including NMOC concentration. A comparison between these two results suggests that the probabilistic outcome is a more representative and reliable estimate of the total annual mass emission of NMOC especially given the variability of the parameters of the model. Moreover, a comparison of the model result and the safety standard of 5.0 x 10-5 kg/year indicate that the mass emission of NMOC from the studied landfill is significantly less than previously thought. However, given that this can accumulate to a dangerous level over a long period of time (such as the age of this landfill site); it may have started affecting the health of the people living within the vicinity of the landfill. A case is therefore made for more studies to be carried out on the emissions of other gases such as CH4 and CO2 from the studied landfill site, as this would help to understand the synergistic effect of the various gases being emitted from the landfill.

  13. Remote Real-Time Monitoring of Subsurface Landfill Gas Migration

    Directory of Open Access Journals (Sweden)

    Alan F. Smeaton

    2011-06-01

    Full Text Available The cost of monitoring greenhouse gas emissions from landfill sites is of major concern for regulatory authorities. The current monitoring procedure is recognised as labour intensive, requiring agency inspectors to physically travel to perimeter borehole wells in rough terrain and manually measure gas concentration levels with expensive hand-held instrumentation. In this article we present a cost-effective and efficient system for remotely monitoring landfill subsurface migration of methane and carbon dioxide concentration levels. Based purely on an autonomous sensing architecture, the proposed sensing platform was capable of performing complex analytical measurements in situ and successfully communicating the data remotely to a cloud database. A web tool was developed to present the sensed data to relevant stakeholders. We report our experiences in deploying such an approach in the field over a period of approximately 16 months.

  14. The Importance of Landfill Gas Policy Measures

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    The purpose of this document is to identify and examine global policies, measures, and incentives that appear to be stimulating LFG use. As certain countries have made great advances in LFGE development through effective policies, the intention of this report is to use information from the IEA's Global Renewable Energy and Energy Efficiency Measures and Policies Databases to identify and discuss policies. By consolidating this information and categorising it according to policy type, the attributes that are most appealing or applicable to the circumstances of a particular country or area -- technology demonstration, financial incentives, awareness campaigns, etc. -- are more easily identified. The report begins with background information on LFG and sanitary landfill practices, including a discussion of regional disparities, followed by a description of LFG mitigation technologies. Barriers to LFGE projects are then outlined. An explanation of the importance and effectiveness of policy measures leads into a discussion of types and examples of measures that are being used to overcome these barriers and encourage LFGE development. The report concludes with lessons learned, recommendations for further study, and resources where more information can be found.

  15. Microbial mitigation of greenhouse gas emissions from landfill cover soils

    Science.gov (United States)

    Lee, Sung-Woo

    Landfills are one of the major sources of methane (CH4), a potent greenhouse gas with a global warming potential (GWP) ˜23 times higher than that of carbon dioxide (CO2). Although some effective strategies have been formulated to prevent methane emissions from large landfills, many landfills allow methane to be freely emitted to the atmosphere. In such situations, it is often proposed to stimulate methanotrophs, a group of bacteria that consume methane, in the cover soil to prevent fugitive methane emissions. Several factors, however, must be addressed to make such a biogenic removal mechanism effective. First, methanotrophic activity can be inhibited by nonmethane organic compounds (NMOCs) that are commonly found in landfill soil gas. Second, although methanotrophs can be easily stimulated with the addition of nitrogenous fertilizers, biogenic production of nitrous oxide with a GWP ˜296 times higher than that of carbon dioxide, is also stimulated. To consider these issues, two general areas of research were performed. First, a dimensionless number was developed based on Michaelis-Menten kinetics that describes the effects of the presence of multiple NMOCs on methanotrophic growth and survival. This model was validated via experimental measurements of methanotrophic growth in the presence of varying amounts of NMOCs. Second, the effects of nutrient amendments on methane oxidation and nitrous oxide production were examined by constructing soil microcosms using landfill cover soils. Here, it was shown that the addition of ammonium in the presence of phenylacetylene stimulated methane oxidation but inhibited nitrous oxide production. Furthermore, to understand the methanotrophic community structure and activity in response to these amendments, DNA microarray and transcript analyses were performed. The results indicated the predominance of Type II methanotrophs but that Type I methanotrophs responded more significantly to these amendments. Also, substantial activity

  16. Mswi bottom ash for upgrading of biogas and landfill gas.

    Science.gov (United States)

    Mostbauer, P; Lenz, S; Lechner, P

    2008-07-01

    A new upgrading process for biogas and landfill gas (LFG) has been designed recently by the authors' institute. The process uses the alkalinity of the fine fraction of bottom ash from municipal solid waste incineration (MSWI) for sorbing CO2 and H2S. Results from process development and optimisation are presented in this paper. It is expected that nearly pure CH4 can be produced for substitution of fossil fuels. Simultaneously, the leachability of MSWI bottom ash is clearly reduced.

  17. Detection of gas in landfills using resistivity measurements; Detektering av gas i deponier med resistivitet

    Energy Technology Data Exchange (ETDEWEB)

    Rosqvist, Haakan; Leroux, Virginie; Lindsjoe, Magnus (NSR AB, Helsingborg (Sweden)); Dahlin, Torleif (Lund Univ., LTH (Sweden)); Svensson, Mats; Maansson, Carl-Henrik (Tyrens AB, Stockholm (Sweden))

    2009-05-15

    The main objective with the research project was to develop a methodology to improve the understanding of landfill gas migration in landfills, based on measurements with electrical resistivity. Consequently, the project aimed at an improvement of the utilisation of the energy potential in landfill gas, and to reduce the environmental impact to the atmosphere. Further more, the objective was to improve techniques for investigations of internal structures in landfills. The project also aimed at better understanding of gas migration in the waste body and the mitigation through a landfill cover. Measurements were performed at four landfills; the Biocell reactor (NSR, Helsingborg), the Filborna landfill (NSR, Helsingborg), the Hyllstofta landfill (Naarab, Klippan) and the Flishult landfill (Vetab, Vetlanda). Three dimensional (3D) measurements and analysis were performed. The measurements were repeated in time in order to study changes with time for the resistivity. Supplementary information was created by measurement of other parameters, such as, groundwater table and soil temperature. The results from the resistivity measurements agreed with previous measurements performed at landfills, and thus, the results are therefore regarded as reliable. The measurements showed large temporal and spatial variations, and all of the measurements showed the highest variability near the surface. The results show that the resistivity technique is a powerful tool for investigations of the internal of landfills. Water and gas migration are important features in landfill management and both processes can be detected by using resistivity. Degradation of organic waste results in process with high variability in time and space. Also the degradation rate varies in a landfill and high variability was registered during the resistivity measurements. The high variability in resistivity is likely to be explained by changes in gas pressure and thus indicating gas migration. Therefore, the project

  18. Climate co-benefits of energy recovery from landfill gas in developing Asian cities: a case study in Bangkok.

    Science.gov (United States)

    Menikpura, S N M; Sang-Arun, Janya; Bengtsson, Magnus

    2013-10-01

    Landfilling is the most common and cost-effective waste disposal method, and it is widely applied throughout the world. In developing countries in Asia there is currently a trend towards constructing sanitary landfills with gas recovery systems, not only as a solution to the waste problem and the associated local environmental pollution, but also to generate revenues through carbon markets and from the sale of electricity. This article presents a quantitative assessment of climate co-benefits from landfill gas (LFG) to energy projects, based on the case of Bangkok Metropolitan Administration, Thailand. Life cycle assessment was used for estimating net greenhouse gas (GHG) emissions, considering the whole lifespan of the landfill. The assessment found that the total GHG mitigation of the Bangkok project would be 471,763 tonnes (t) of carbon dioxide (CO(2))-equivalents (eq) over its 10-year LFG recovery period.This amount is equivalent to only 12% of the methane (CH(4)) generated over the whole lifespan of the landfill. An alternative scenario was devised to analyse possible improvement options for GHG mitigation through LFG-to-energy recovery projects. This scenario assumes that LFG recovery would commence in the second year of landfill operation and gas extraction continues throughout the 20-year peak production period. In this scenario, GHG mitigation potential amounted to 1,639,450 tCO(2)-eq during the 20-year project period, which is equivalent to 43% of the CH(4) generated throughout the life cycle. The results indicate that with careful planning, there is a high potential for improving the efficiency of existing LFG recovery projects which would enhance climate co-benefits, as well as economic benefits. However, the study also shows that even improved gas recovery systems have fairly low recovery rates and, in consequence, that emissions of GHG from such landfills sites are still considerable.

  19. Quantification of parameters influencing methane generation due to biodegradation of municipal solid waste in landfills and laboratory experiments.

    Science.gov (United States)

    Fei, Xunchang; Zekkos, Dimitrios; Raskin, Lutgarde

    2016-09-01

    The energy conversion potential of municipal solid waste (MSW) disposed of in landfills remains largely untapped because of the slow and variable rate of biogas generation, delayed and inefficient biogas collection, leakage of biogas, and landfill practices and infrastructure that are not geared toward energy recovery. A database consisting of methane (CH4) generation data, the major constituent of biogas, from 49 laboratory experiments and field monitoring data from 57 landfills was developed. Three CH4 generation parameters, i.e., waste decay rate (k), CH4 generation potential (L0), and time until maximum CH4 generation rate (tmax), were calculated for each dataset using U.S. EPA's Landfill Gas Emission Model (LandGEM). Factors influencing the derived parameters in laboratory experiments and landfills were investigated using multi-linear regression analysis. Total weight of waste (W) was correlated with biodegradation conditions through a ranked classification scheme. k increased with increasing percentage of readily biodegradable waste (Br0 (%)) and waste temperature, and reduced with increasing W, an indicator of less favorable biodegradation conditions. The values of k obtained in the laboratory were commonly significantly higher than those in landfills and those recommended by LandGEM. The mean value of L0 was 98 and 88L CH4/kg waste for laboratory and field studies, respectively, but was significantly affected by waste composition with ranges from 10 to 300L CH4/kg. tmax increased with increasing percentage of biodegradable waste (B0) and W. The values of tmax in landfills were higher than those in laboratory experiments or those based on LandGEM's recommended parameters. Enhancing biodegradation conditions in landfill cells has a greater impact on improving k and tmax than increasing B0. Optimizing the B0 and Br0 values of landfilled waste increases L0 and reduces tmax.

  20. Landfill Gas Electricity Project Interconnection Webinar

    Science.gov (United States)

    This page contains information about a webinar LMOP offered to LMOP Partners to address questions associated with connecting electricity generating systems to the grid during LFG energy project planning and implementation.

  1. SLIPPAGE SOLUTION OF GAS PRESSURE DISTRIBUTION IN PROCESS OF LANDFILL GAS SEEPAGE

    Institute of Scientific and Technical Information of China (English)

    XUE Qiang; FENG Xia-ting; LIANG Bing

    2005-01-01

    A mathematical model of landfill gas migration was established under presumption of the effect of gas slippage. The slippage solutions to the nonlinear mathematical model were accomplished by the perturbation and integral transformation method. The distribution law of gas pressure in landfill site was presented under the conditions of considering and neglecting slippage effect. Sensitivity of the model input parameters was analyzed. The model solutions were compared to observation values.Results show that gas slippage effect has a large impact on gas pressure distribution.Landfill gas pressure and pressure gradient considering slippage effect is lower than that neglecting slippage effect, with reasonable agreement between model solution and measured data. It makes clear that the difference between considering and neglecting slippage effect is obvious and the effects of coupling cannot be ignored. The theoretical basis is provided for engineering design of security control and decision making of gas exploitation in landfill site. The solutions give scientific foundation to analyzing well test data in the process of low-permeability oil gas reservoir exploitation.

  2. Quantitative Study of Biogas Generation Potential from Different Landfill Sites of Nepal

    Directory of Open Access Journals (Sweden)

    Bikash Adhikari

    2015-01-01

    Full Text Available This research paper was study of waste composition and quantitative analysis of biogas generation potential with its recovery at Sisdole, Pokhara and Karaute Dada landfill sites (LFS of Nepal. The waste management practice in LFS are significant deciding factors for the assessment of environmental impacts caused including the release of green house gases like methane, carbondioxide etc to the atmosphere, that could contribute significantly to global warming and climate change. The total waste disposed to Sisdole LFS, Pokhara LFS and Karaute Dada LFS are 410, 80 and 7.8 tons respectively.  The waste composition was studied onsite with waste reduction method and analyzed for their composition. The organic component of wastes was found high as 61.6%, 52.5% and 65% at Sisdole, Pokhara and Karaute Dada LFS respectively. The biogas potential at these landfill sites were 12157.78 cum, 851.99 cum and 169 cum of biogas per day in Sisdole, Pokhara and Karaute Dada LFS respectively. 4.68, 0.33 and 0.07 MW energy per day can be generated from these amounts of biogas produced in Sisdole, Pokhara and Karaute Dada LFS respectively. Proper gas collection system can be the source of income from these landfill sites and help to mitigate the adverse impact of methane that is being released from these landfill sites

  3. Standardization of the Electricity and Economic Potentials of Landfill gas (LFG in Lagos, Nigeria.

    Directory of Open Access Journals (Sweden)

    Christopher N AKUJIEZE

    2014-05-01

    Full Text Available Globally, various practical data and scholarly estimations of the electricity potentials of landfill gas (LFG have been forwarded and these can be juxtaposed for estimations in the megacity called Lagos. The calculated values were between 63.22- 700MW of  derivable electricity. However, in order to limit observable disparities and ambiguities in these derivations and thus allow for more accurate projections, these estimations can be gauged using as template; -stoichiometry, establishing 50% of landfill gas as methane, assuming 50% of this volume as recoverable, and using a proposed engine efficiency of 30%. This standardization projects a theoretical mean achievable electrical power of 121.69 MW for the Lagos area from a population of about 21 million with a generation per capita (GPC of 0.63kg with biodegradable content of about 60%. The yearly electrical energy was placed at 1,066,004.4 MWh with tariff revenue in excess of US$ 106.6 million /yr. An accruing carbon credit of about US$75.59 million /yr is expected from certified emission reduction (CER. The projected derivations can be used as models for evaluation of the landfill gas and electricity potentials in many parts of the world.

  4. Development of the utilization of combustible gas produced in existing sanitary landfills: Effects of corrosion at the Mountain View, California landfill gas-recovery plant

    Science.gov (United States)

    1982-10-01

    Corrosion of equipment has occurred at the Mountain View, California Landfill Gas Recovery Plant. Corrosion is most severe on compressor valve seats and cages, tubes in the first and second stages of the interstage gas cooler, and first and second stage piping and liquid separators. Corrosion occurs because the raw landfill gas contains water, carbon dioxide, and oxygen. Some corrosion may also result from trace concentrations of organic acids present in the landfill gas. Corrosion of the third stage compressor, cooler, and piping does not occur because the gas is dehydrated immediately prior to the third stage. Controlling corrosion is necessary to maintain the mechanical integrity of the plant and to keep the cost of the gas competitive with natural gas. Attempts to reduce corrosion rates by injecting a chemical inhibitor have proved only partially successful. Recommendations for dealing with corrosion include earlier dehydration of the gas, selection of special alloys in critical locations, chemical inhibition, and regular plant inspections.

  5. Mitigation of methane emissions in a pilot-scale biocover system at the AV Miljø Landfill, Denmark: 1. System design and gas distribution

    DEFF Research Database (Denmark)

    Cassini, Filippo; Scheutz, Charlotte; Skov, Bent Henning

    2017-01-01

    Greenhouse gas mitigation at landfills by methane oxidation in engineered biocover systems is believed to be a cost effective technology, but so far a full quantitative evaluation of the efficiency of the technology in full scale has only been carried out in a few cases. A third generation semi......-passive biocover system was constructed at the AV Miljø Landfill, Denmark. The biocover system was fed by landfill gas pumped out of three leachate collection wells. An innovative gas distribution system was used to overcome the commonly observed surface emission hot spot areas resulting from an uGreenhouse gas...... mitigation at landfills by methane oxidation in engineered biocover systems is believed to be a cost effective technology, but so far a full quantitative evaluation of the efficiency of the technology in full scale has only been carried out in a few cases. A third generation semi-passive biocover system...

  6. Estimation of emissions of nonmethane organic compounds from a closed landfill site using a landfill gas emission model

    Directory of Open Access Journals (Sweden)

    A. N. Nwachukwu, A. W. Diya

    2013-01-01

    Full Text Available Nonmethane organic compounds (NMOC emissions from landfills often constitute significant risks both to human health and the general environment. To date very little work has been done on tracking the emissions of NMOC from landfills. To this end, a concerted effort was made to investigate the total annual mass emission rate of NMOC from a closed landfill site in South Manchester, United Kingdom. This was done by using field estimates of NMOC concentration and the landfill parameters into the Landfill Gas Emission Model embedded in ACTS and RISK software. Two results were obtained: (i a deterministic outcome of 1.7218 x 10-7 kg/year, which was calculated from mean values of the field estimates of NMOC concentration and the landfill parameters, and (ii a probabilistic outcome of 1.66 x 10-7 - 1.78 x 10-7 kg/year, which is a range of value obtained after Monte Carlo simulation of the uncertain parameters of the landfill including NMOC concentration. A comparison between these two results suggests that the probabilistic outcome is a more representative and reliable estimate of the total annual mass emission of NMOC especially given the variability of the parameters of the model. Moreover, a comparison of the model result and the safety standard of 5.0 x 10-5 kg/year indicate that the mass emission of NMOC from the studied landfill is significantly less than previously thought. However, given that this can accumulate to a dangerous level over a long period of time (such as the age of this landfill site; it may have started affecting the health of the people living within the vicinity of the landfill. A case is therefore made for more studies to be carried out on the emissions of other gases such as CH4 and CO2 from the studied landfill site, as this would help to understand the synergistic effect of the various gases being emitted from the landfill.

  7. Modeling lateral gas transport in soil adjacent to an old landfill

    DEFF Research Database (Denmark)

    Poulsen, T.G.; Christophersen, Mette; Moldrup, P.

    2001-01-01

    Lateral migration of landfill gases in soils surrounding old (closed) municipal landfills can lead to explosion hazards and damage to vegetation. Landfill gas production and migration is controlled by microbial activity and soil physical properties such as gas (air) permeability, gas diffusivity....... An empirical expression for calculating methane oxidation rate as a function of soil temperature was developed using site-specific measurements of methane oxidation rate. The transport and degradation parameter expressions were incorporated into a numerical model for simulating landfill gas transport, using...... soil-water content, temperature, and soil organic matter content as measured input parameters (functions of time and soil depth). Previous measurements of landfill gas (CO2 and CH4) concentrations and fluxes in the agricultural field soil conducted over a period of one year were used to calibrate...

  8. Promotion of landfill gas recovering in Denmark; Fremme af lossepladsgas-udnyttelse i Danmark

    Energy Technology Data Exchange (ETDEWEB)

    Willumsen, H.C.

    1998-12-01

    The primary objective for the Danish Energy Agency with this project has been to increase the number of landfill gas plants in Denmark where the gas may used for energy purposes. This will fulfil some of the aims in Energy 21 where landfill gas is one of the possibilities in the area of biomass. The recovery and utilisation of landfill gas and the replacement of fossil fuels with CO{sub 2} neutral energy sources will mean a reduction of emission of methane and a reduction of greenhouse gases. The report contains investigations of a number of landfills in Denmark. For each landfill is listed the size, amount of waste, and type of waste. From these figures are made an estimate of the gas production over the next 20 years. (SM)

  9. Generation of leachate and the flow regime in landfills

    Energy Technology Data Exchange (ETDEWEB)

    Bendz, D.

    1998-06-01

    In this thesis the generation of leachate and the presence and movement of water in landfilled municipal solid waste (MSW) is investigated. The precipitation-leachate discharge relationship for landfills was found to be dominated by evaporation, accumulation in the soil cover, accumulation in the solid waste and fast gravitational flow in a network of channels. The flow regime is governed by the heterogeneity of the internal geometry of the landfill, which is characterized by a discrete structure, significant horizontal stratification, structural voids, impermeable surfaces, and low capillarity. Also the boundary conditions, that is the water input pattern, has shown to be important for the flow process. Based on this, landfilled waste can be conceptualized as a dual domain medium, consisting of a channel domain and a matrix domain. The matrix flow is slow and diffusive, whereas the channel flow is assumed to be driven solely by gravity and to take place as a thin viscous film on solid surfaces. A kinematic wave model for unsaturated infiltration and internal drainage in the channel domain is presented. The model employs a two-parameter power expression as macroscopic flux law. Solutions were derived for the cases when water enters the channel domain laterally and when water enters from the upper end. The model parameters were determined and interpreted in terms of the internal geometry of the waste medium by fitting the model to one set of infiltration and drainage data derived from a large scale laboratory experiment under transient conditions. The model was validated using another set of data from a sequence of water input events and was shown to perform accurately. A solute transport model was developed by coupling a simple piston flux expression and a mobile-immobile conceptualization of the transport domains with the water flow model. Breakthrough curves derived from steady and transient tracer experiments where interpreted with the model. The transport

  10. Long and short term pump testing for landfill gas wells

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, D.W.; Fleming, I.R. [Saskatchewan Univ., Saskatoon, SK (Canada). Dept. of Civil and Geological Engineering

    2009-07-01

    A study was conducted to evaluate vertical well designs drilled into existing landfills as part of a landfill gas collection retrofitting project. Well designs and construction techniques were compared in relation to pneumatic efficiency and the capacity of each well. The aim of the study was to devise a method of evaluating well efficiency and long-term performance. Short-term, single well step-drawdown tests were conducted. Long-term pumping from the entire well field was conducted using different flow rate control approaches. Flow rates were measured at several different system pressures. Data were then compared with drawdown flow rate data from the short-term tests. The study proved that the single well short-term tests accurately predicted the long-term performance of the well field. The study also demonstrated that there was no apparent relationship between well productivity and the length of the screened zone, the diameter of the well, or the diameter of the borehole. No relationship was observed between well performance and the capital costs of individual wells.

  11. Landfill Gas Energy Cost Model Version 3.0 (LFGcost-Web V3 ...

    Science.gov (United States)

    To help stakeholders estimate the costs of a landfill gas (LFG) energy project, in 2002, LMOP developed a cost tool (LFGcost). Since then, LMOP has routinely updated the tool to reflect changes in the LFG energy industry. Initially the model was designed for EPA to assist landfills in evaluating the economic and financial feasibility of LFG energy project development. In 2014, LMOP developed a public version of the model, LFGcost-Web (Version 3.0), to allow landfill and industry stakeholders to evaluate project feasibility on their own. LFGcost-Web can analyze costs for 12 energy recovery project types. These project costs can be estimated with or without the costs of a gas collection and control system (GCCS). The EPA used select equations from LFGcost-Web to estimate costs of the regulatory options in the 2015 proposed revisions to the MSW Landfills Standards of Performance (also known as New Source Performance Standards) and the Emission Guidelines (herein thereafter referred to collectively as the Landfill Rules). More specifically, equations derived from LFGcost-Web were applied to each landfill expected to be impacted by the Landfill Rules to estimate annualized installed capital costs and annual O&M costs of a gas collection and control system. In addition, after applying the LFGcost-Web equations to the list of landfills expected to require a GCCS in year 2025 as a result of the proposed Landfill Rules, the regulatory analysis evaluated whether electr

  12. Liquid propellant gas generators

    Science.gov (United States)

    1972-01-01

    The design of gas generators intended to provide hot gases for turbine drive is discussed. Emphasis is placed on the design and operation of bipropellant gas generators because of their wider use. Problems and limitations involved in turbine operation due to temperature effects are analyzed. Methods of temperature control of gas turbines and combustion products are examined. Drawings of critical sections of gas turbines to show their operation and areas of stress are included.

  13. From a Literature Review to an Alternative Treatment System for Landfill Gas and Leachate

    Directory of Open Access Journals (Sweden)

    Tao Huang

    2012-12-01

    Full Text Available This paper provides an alternative treatment system for landfill gas and leachate control in order to reduce the energy consumption and disposal cost, using the recycled landfill gas as the combustion promoter for incineration of the leachate. This study starts by providing a literature review to summarize and analyze different approaches being applied to landfill leachate treatment. Subsequently, a conceptual prototype is proposed, which can be built using existing technology by means of technical possibility analysis, whilst economic benefits could be returned through preliminary comparison. With the proposed introduction of a “waste treatment park”, this alternative treatment system could provide a template for leachate and landfill gas control. This study may provide an insight for landfill operators and engineers to promote the transformation from the conceptual framework to the real achievement. Finally, the limitations of the conceptual model and analysis are discussed, laying a foundation for further work.

  14. Landfill gas (LFG) processing via adsorption and alkanolamine absorption

    Energy Technology Data Exchange (ETDEWEB)

    Gaur, Ankur; Park, Jin-Won; Song, Ho-Jun; Park, Jong-Jin [Department of Chemical and Biomolecular Engineering, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul 120-749 (Korea); Maken, Sanjeev [Department of Chemistry, Deenbandhu Chhotu Ram University of Science and Technology, Murthal-131 039, Haryana (India)

    2010-06-15

    Landfill gas (LFG) was upgraded to pure methane using the adsorption and absorption processes. Different toxic compounds like aromatics and chlorinated compounds were removed using granular activated carbon. The activated carbon adsorbed toxic trace components in the following order: carbon tetrachloride > toluene > chloroform > xylene > ethylbenzene > benzene > trichloroethylene {approx} tetrachloroethylene. After removing all trace components, the gas was fed to absorption apparatus for the removal of carbon dioxide (CO{sub 2}). Two alkanolamines, monoethanol amine (MEA) and diethanol amine (DEA) were used for the removal of CO{sub 2} from LFG. The maximum CO{sub 2} loading is obtained for 30 wt.% MEA which is around 2.9 mol L{sup -} {sup 1} of absorbent solution whereas for same concentration of DEA it is around 1.66 mol L {sup -} {sup 1} of solution. 30 wt% MEA displayed a higher absorption rate of around 6.64 x 10{sup -} {sup 5} mol L{sup -} {sup 1} min{sup -} {sup 1}. DEA displayed a higher desorption rate and a better cyclic capacity as compared to MEA. Methane obtained from this process can be further used in the natural gas network for city. (author)

  15. Greenhouse gas emissions from landfill leachate treatment plants: A comparison of young and aged landfill

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiaojun, E-mail: xjwang@iue.ac.cn [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Jia, Mingsheng, E-mail: msjia@iue.ac.cn [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Chen, Xiaohai, E-mail: cxiaoh_xm@126.com [Xiamen City Environmental Sanitation Management Department, Xiamen 361000 (China); Xu, Ying, E-mail: yxu@iue.ac.cn [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Lin, Xiangyu, E-mail: xylin@iue.ac.cn [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Kao, Chih Ming, E-mail: jkao@mail.nsysu.edu.tw [Institute of Environmental Engineering, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan (China); Chen, Shaohua, E-mail: shchen@iue.ac.cn [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China)

    2014-07-15

    Highlights: • Young and aged leachate works accounted for 89.1% and 10.9% of 33.35 Gg CO{sub 2} yr{sup −1}. • Fresh leachate owned extremely low ORP and high organic matter content. • Strong CH{sub 4} emissions occurred in the fresh leachate ponds, but small in the aged. • N{sub 2}O emissions became dominant in the treatment units of both systems. • 8.45–11.9% of nitrogen was removed as the form of N{sub 2}O under steady-state. - Abstract: With limited assessment, leachate treatment of a specified landfill is considered to be a significant source of greenhouse gas (GHG) emissions. In our study, the cumulative GHG emitted from the storage ponds and process configurations that manage fresh or aged landfill leachate were investigated. Our results showed that strong CH{sub 4} emissions were observed from the fresh leachate storage pond, with the fluxes values (2219–26,489 mg C m{sup −2} h{sup −1}) extremely higher than those of N{sub 2}O (0.028–0.41 mg N m{sup −2} h{sup −1}). In contrast, the emission values for both CH{sub 4} and N{sub 2}O were low for the aged leachate tank. N{sub 2}O emissions became dominant once the leachate entered the treatment plants of both systems, accounting for 8–12% of the removal of N-species gases. Per capita, the N{sub 2}O emission based on both leachate treatment systems was estimated to be 7.99 g N{sub 2}O–N capita{sup −1} yr{sup −1}. An increase of 80% in N{sub 2}O emissions was observed when the bioreactor pH decreased by approximately 1 pH unit. The vast majority of carbon was removed in the form of CO{sub 2}, with a small portion as CH{sub 4} (<0.3%) during both treatment processes. The cumulative GHG emissions for fresh leachate storage ponds, fresh leachate treatment system and aged leachate treatment system were 19.10, 10.62 and 3.63 Gg CO{sub 2} eq yr{sup −1}, respectively, for a total that could be transformed to 9.09 kg CO{sub 2} eq capita{sup −1} yr{sup −1}.

  16. Thermal inactivation of Bacillus anthracis surrogate spores in a bench-scale enclosed landfill gas flare.

    Science.gov (United States)

    Tufts, Jenia A McBrian; Rosati, Jacky A

    2012-02-01

    A bench-scale landfill flare system was designed and built to test the potential for landfilled biological spores that migrate from the waste into the landfill gas to pass through the flare and exit into the environment as viable. The residence times and temperatures of the flare were characterized and compared to full-scale systems. Geobacillus stearothermophilus and Bacillus atrophaeus, nonpathogenic spores that may serve as surrogates for Bacillus anthracis, the causative agent for anthrax, were investigated to determine whether these organisms would be inactivated or remain viable after passing through a simulated landfill flare. High concentration spore solutions were aerosolized, dried, and sent through a bench-scale system to simulate the fate of biological weapon (BW)-grade spores in a landfill gas flare. Sampling was conducted downstream of the flare using a bioaerosol collection device containing sterile white mineral oil. The samples were cultured, incubated for seven days, and assessed for viability. Results showed that the bench-scale system exhibited good similarity to the real-world conditions of an enclosed standard combustor flare stack with a single orifice, forced-draft diffusion burner. All spores of G. stearothermophilus and B. atrophaeus were inactivated in the flare, indicating that spores that become re-entrained in landfill gas may not escape the landfill as viable, apparently becoming completely inactivated as they exit through a landfill flare.

  17. Greenhouse gas emissions through cap barriers of landfills

    Energy Technology Data Exchange (ETDEWEB)

    Gourc, J.P.; Staub, M.; Simonin, R. [Grenoble Univ. (France). LTHE

    2009-07-01

    A study was conducted to examine the environmental impacts of landfill cap covers used to produce biogas. The sensitivity of the environmental performance of landfills on biogas collection and recovery systems as well as on cap cover characteristics was investigated. The study examined both soil and geosynthetic landfill cap covers used to maintain impermeability at landfill sites as well as to enable biogas recovery. Two types of cap cover were discussed: (1) a cover that enabled passive wetting of the landfill wastes through rainfall; and (2) an impermeable cap used to control leachate recirculation. The environmental impacts of both caps were discussed. The study showed that landfill cap covers are a significant means of sequestering greenhouse gases (GHGs).

  18. Landfill Top Covers

    DEFF Research Database (Denmark)

    Scheutz, Charlotte; Kjeldsen, Peter

    2011-01-01

    the landfill section has been filled or several years later depending on the settlement patterns. Significant differential settlements may disturb the functioning of the top cover. The specific design of the cover system depends on the type of waste landfilled (municipal, hazardous, or inert waste...... such as lowpermeability clay soils and geomembranes are required. The avoidance of water input to organic waste may impede the microbial stabilization processes including gas generation. Therefore watertight top covers may be in conflict with the purposes of reactor landfills (see Chapter 10.6). At some sites covers...... sometimes are made to include components for recirculation of landfill leachate (see Section 10.9.2 for more details). The top cover is an important factor in the water management of landfills. Details about water infiltration through top covers and its influence on the hydrology of the landfill is covered...

  19. LANDFILL BIOREACTOR PERFORMANCE, SECOND INTERIM REPORT

    Science.gov (United States)

    A bioreactor landfill is a landfill that is operated in a manner that is expected to increase the rate and extent of waste decomposition, gas generation, and settlement compared to a traditional landfill. This Second Interim Report was prepared to provide an interpretation of fie...

  20. LANDFILL BIOREACTOR PERFORMANCE, SECOND INTERIM REPORT

    Science.gov (United States)

    A bioreactor landfill is a landfill that is operated in a manner that is expected to increase the rate and extent of waste decomposition, gas generation, and settlement compared to a traditional landfill. This Second Interim Report was prepared to provide an interpretation of fie...

  1. Translating landfill methane generation parameters among first-order decay models.

    Science.gov (United States)

    Krause, Max J; Chickering, Giles W; Townsend, Timothy G

    2016-11-01

    Landfill gas (LFG) generation is predicted by a first-order decay (FOD) equation that incorporates two parameters: a methane generation potential (L0) and a methane generation rate (k). Because non-hazardous waste landfills may accept many types of waste streams, multiphase models have been developed in an attempt to more accurately predict methane generation from heterogeneous waste streams. The ability of a single-phase FOD model to predict methane generation using weighted-average methane generation parameters and tonnages translated from multiphase models was assessed in two exercises. In the first exercise, waste composition from four Danish landfills represented by low-biodegradable waste streams was modeled in the Afvalzorg Multiphase Model and methane generation was compared to the single-phase Intergovernmental Panel on Climate Change (IPCC) Waste Model and LandGEM. In the second exercise, waste composition represented by IPCC waste components was modeled in the multiphase IPCC and compared to single-phase LandGEM and Australia's Solid Waste Calculator (SWC). In both cases, weight-averaging of methane generation parameters from waste composition data in single-phase models was effective in predicting cumulative methane generation from -7% to +6% of the multiphase models. The results underscore the understanding that multiphase models will not necessarily improve LFG generation prediction because the uncertainty of the method rests largely within the input parameters. A unique method of calculating the methane generation rate constant by mass of anaerobically degradable carbon was presented (kc) and compared to existing methods, providing a better fit in 3 of 8 scenarios. Generally, single phase models with weighted-average inputs can accurately predict methane generation from multiple waste streams with varied characteristics; weighted averages should therefore be used instead of regional default values when comparing models. Translating multiphase first

  2. Environmental assessment of gas management options at the Old Ämmässuo landfill (Finland) by means of LCA-modeling (EASEWASTE)

    DEFF Research Database (Denmark)

    Manfredi, Simone; Niskanen, A.; Christensen, Thomas Højlund

    2009-01-01

    option - as it has the highest LEG utilization/energy recovery rates - whereas the worst performance is estimated for the LEG flaring option, as no LEG is here Utilized for energy generation. Therefore, to reduce the environmental burdens caused by the Current gas management strategy, more LEG should......The current landfill gas (LFG) management (based on flaring and utilization for heat generation of the collected gas) and three potential future gas management options (LFG flaring, heat generation and combined heat and power generation) for the Old Ammassuo landfill (Espoo, Finland) were evaluated...... by life-cycle assessment modeling. The evaluation accounts for all resource utilization and emissions to the environment related to the gas generation and management for a life-cycle time horizon of 100 yr. The assessment criteria comprise standard impact categories (global warming, photo-chemical ozone...

  3. Numerical modelling of methane oxidation efficiency and coupled water-gas-heat reactive transfer in a sloping landfill cover.

    Science.gov (United States)

    Feng, S; Ng, C W W; Leung, A K; Liu, H W

    2017-10-01

    Microbial aerobic methane oxidation in unsaturated landfill cover involves coupled water, gas and heat reactive transfer. The coupled process is complex and its influence on methane oxidation efficiency is not clear, especially in steep covers where spatial variations of water, gas and heat are significant. In this study, two-dimensional finite element numerical simulations were carried out to evaluate the performance of unsaturated sloping cover. The numerical model was calibrated using a set of flume model test data, and was then subsequently used for parametric study. A new method that considers transient changes of methane concentration during the estimation of the methane oxidation efficiency was proposed and compared against existing methods. It was found that a steeper cover had a lower oxidation efficiency due to enhanced downslope water flow, during which desaturation of soil promoted gas transport and hence landfill gas emission. This effect was magnified as the cover angle and landfill gas generation rate at the bottom of the cover increased. Assuming the steady-state methane concentration in a cover would result in a non-conservative overestimation of oxidation efficiency, especially when a steep cover was subjected to rainfall infiltration. By considering the transient methane concentration, the newly-modified method can give a more accurate oxidation efficiency. Copyright © 2017. Published by Elsevier Ltd.

  4. Yolo County controlled landfill project

    Energy Technology Data Exchange (ETDEWEB)

    Augenstein, D. [IEM, Palo Alto, CA (United States); Yazdani, R.; Dahl, K.; Mansoub, A.; Moore, R. [Yolo County Department of Public Works, Davis, CA (United States); Pacey, J. [Emcon, San Mateo, CA (United States)

    1999-07-01

    A new landfill management approach controlled landfilling is being demonstrated by the Yolo County, California Department of Public Works at the Yolo County Central Landfill (YCCL) near Davis. Overall objectives are to obtain earlier and greater methane energy recovery from landfilled waste and to reduce landfill greenhouse gas emissions to near-negligible levels. Methane generation and waste stabilization were accelerated by improving biological conditions within a test cell through carefully controlled additions of water and leachate. A control cell was operated in parallel. Landfill gas capture was maximized, with emissions reduced to minimal levels, by a combination of surface membrane containment, a permeable layer conducting gas to collection points, and operation at slight vacuum. Cells are highly instrumented to determine performance. To date, normalized methane recovery is the highest seen from such a large waste mass, anywhere - about ten times that from conventional landfall practice. The rationale and details of this project, and first three years' results, are summarized. (author)

  5. Microbial methane oxidation processes and technologies for mitigation of landfill gas emissions

    DEFF Research Database (Denmark)

    Scheutz, Charlotte; Kjeldsen, Peter; Bogner, J.E.;

    2009-01-01

    utilizing oxygen that diffuses into the cover layer from the atmosphere. The methane oxidation process, which is governed by several environmental factors, can be exploited in engineered systems developed for methane emission mitigation. Mathematical models that account for methane oxidation can be used...... to predict methane emissions from landfills. Additional research and technology development is needed before methane mitigation technologies utilizing microbial methane oxidation processes can become commercially viable and widely deployed.......Landfill gas containing methane is produced by anaerobic degradation of organic waste. Methane is a strong greenhouse gas and landfills are one of the major anthropogenic sources of atmospheric methane. Landfill methane may be oxidized by methanotrophic microorganisms in soils or waste materials...

  6. [On-site measurement of landfill gas yield and verification of IPCC model].

    Science.gov (United States)

    Luo, Yu-Xiang; Wang, Wei; Gao, Xing-Bao

    2009-11-01

    In order to obtain the accurate yield of landfill gas in Yulongkeng Landfill, Shenzhen, improved pumping test was conducted. The methane production rates of the influence region were figured out as 14.67 x 10(-5), 9.46 x 10(-5), 9.55 x 10(-5), and 4.28 x 10(-5) m3/(t x h), respectively. According to the methane production rate, the whole methane yield of Yulongkeng Landfill in 2005 was 322 m3/h, which indicated that Yulongkeng Landfill had went into stationary phase and the recycle of landfill gas was not valuable. IPCC model was verified by the measured data. Degradation half life of the waste was the key parameter concerned to the prediction accuracy of IPCC model. In China, the degradable waste in municipal solid waste was mainly kitchen waste leading to a short degradation period, which caused the degradation half life was shorter than the proposed value in IPCC model. For the improvement in prediction accuracy of landfill gas yield, the model parameters should be adopted reasonably based on a full survey of waste characterization in China, which will boost the applicability of IPCC model.

  7. LANDFILL OPERATION FOR CARBON SEQUESTRATION AND MAXIMUM METHANE EMISSION CONTROL

    Energy Technology Data Exchange (ETDEWEB)

    Don Augenstein

    1999-01-11

    ''Conventional'' waste landfills emit methane, a potent greenhouse gas, in quantities such that landfill methane is a major factor in global climate change. Controlled landfilling is a novel approach to manage landfills for rapid completion of total gas generation, maximizing gas capture and minimizing emissions of methane to the atmosphere. With controlled landfilling, methane generation is accelerated and brought to much earlier completion by improving conditions for biological processes (principally moisture levels) in the landfill. Gas recovery efficiency approaches 100% through use of surface membrane cover over porous gas recovery layers operated at slight vacuum. A field demonstration project's results at the Yolo County Central Landfill near Davis, California are, to date, highly encouraging. Two major controlled landfilling benefits would be the reduction of landfill methane emissions to minuscule levels, and the recovery of greater amounts of landfill methane energy in much shorter times than with conventional landfill practice. With the large amount of US landfill methane generated, and greenhouse potency of methane, better landfill methane control can play a substantial role in reduction of US greenhouse gas emissions.

  8. DEMONSTRATION OF FUEL CELLS TO RECOVER ENERGY FROM LANDFILL GAS: PHASE II. PRETREATMENT SYSTEM PERFORMANCE MEASUREMENT

    Science.gov (United States)

    The report describes Phase II of a demonstration of the utilization of commercial phosphoric acid fuel cells to recover energy from landfill gas. This phase consisted primarily of the construction and testing of a Gas Pretreatment Unit (GPU) whose function is to remove those impu...

  9. Landfilling: Hydrology

    DEFF Research Database (Denmark)

    Kjeldsen, Peter; Beaven, R.

    2011-01-01

    Landfill hydrology deals with the presence and movement of water through a landfill. The main objective in landfill hydrology is usually to predict leachate generation, but the presence and movement of water in a landfill also affect the degradation of the waste, the leaching of pollutants...... and the geotechnical stability of the fill. Understanding landfill hydrology is thus important for many aspects of landfill, in particular siting, design and operation. The objective of this chapter is to give a basic understanding of the hydrology of landfills, and to present ways to estimate leachate quantities......-circuiting. In the final section different existing hydrological models for landfills are presented with a special focus on the HELP model. This model is the most widely used tool for the prediction of leachate quantities in landfills, and for the sizing of leachate control and management infrastructure....

  10. Landfilling: Hydrology

    DEFF Research Database (Denmark)

    Kjeldsen, Peter; Beaven, R.

    2011-01-01

    Landfill hydrology deals with the presence and movement of water through a landfill. The main objective in landfill hydrology is usually to predict leachate generation, but the presence and movement of water in a landfill also affect the degradation of the waste, the leaching of pollutants...... and the geotechnical stability of the fill. Understanding landfill hydrology is thus important for many aspects of landfill, in particular siting, design and operation. The objective of this chapter is to give a basic understanding of the hydrology of landfills, and to present ways to estimate leachate quantities......-circuiting. In the final section different existing hydrological models for landfills are presented with a special focus on the HELP model. This model is the most widely used tool for the prediction of leachate quantities in landfills, and for the sizing of leachate control and management infrastructure....

  11. Greenhouse gas emissions from two-stage landfilling of municipal solid waste

    Science.gov (United States)

    Zhang, Yuanyuan; Yue, Dongbei; Nie, Yongfeng

    2012-08-01

    Simulations were conducted to investigate greenhouse gas emissions from aerobic pretreatment and subsequent landfilling. The flows in carbon balance, such as gas, leachate, and solid phases, were considered in the simulations. The total amount of CO2 eq. decreased as organic removal efficiency (ORE) increased. At ORE values of 0, 0.30, 0.41, and 0.54, the total amounts of CO2 eq. were 2614, 2326, 2075, and 1572 kg CO2 eq. per one ton dry matter, respectively; gas accounted for the main contribution to the total amount. The reduction in CO2 eq. from leachate was the primary positive contribution, accounting for 356%, 174%, and 100% of total reduction at ORE values of 0.30, 0.41, and 0.54, respectively. The CO2 eq. from energy consumption was the negative contribution to total reduction, but this contribution is considerably lower than that from gas. Aerobic pretreatment shortened the lag time of biogas production by 74.1-97.0%, and facilitated the transfer of organic carbon in solid waste from uncontrolled biogas and highly polluting leachate to aerobically generated CO2.

  12. Mitigation of methane emissions in a pilot-scale biocover system at the av miljø landfill, denmark: system design and gas distribution

    DEFF Research Database (Denmark)

    Kjeldsen, Peter; Skov, B.; Cassini, Filippo

    2013-01-01

    Greenhouse gas mitigation at landfills by methane oxidation in engineered biocover systems is believed to be a cost effective technology but so far a full quantitative evaluation of the efficiency of the technology in full scale has only been carried out in a few cases. A third generation semi-pa...

  13. Relating landfill gas emissions to atmospheric pressure using numerical modeling and state-space analysis

    DEFF Research Database (Denmark)

    Poulsen, T.G.; Christophersen, Mette; Moldrup, P.

    2003-01-01

    were applied: (I) State-space analysis was used to identify relations between gas flux and short-term (hourly) variations in atmospheric pressure. (II) A numerical gas transport model was fitted to the data and used to quantify short-term impacts of variations in atmospheric pressure, volumetric soil......-water content, soil gas permeability, soil gas diffusion coefficients, and biological CH4 degradation rate upon landfill gas concentration and fluxes in the soil. Fluxes and concentrations were found to be most sensitive to variations in volumetric soil water content, atmospheric pressure variations and gas...... permeability whereas variations in CH4 oxidation rate and molecular coefficients had less influence. Fluxes appeared to be most sensitive to atmospheric pressure at intermediate distances from the landfill edge. Also overall CH4 fluxes out of the soil over longer periods (years) were largest during periods...

  14. Application of close-range aerial infrared thermography to detect landfill gas emissions: a case study

    Science.gov (United States)

    Tanda, G.; Migliazzi, M.; Chiarabini, V.; Cinquetti, P.

    2017-01-01

    Monitoring waste disposal sites is important to check that the produced biogas, potentially explosive, is properly collected by the biogas extraction system of the landfill site and to evaluate the residual biogas flow escaping from upper surface of the landfill. As the biogas migrates to the surface, the soil through which it flows is expected to reach a higher temperature than the surrounding environment; thus, measuring the thermal footprint of the landfill soil surface could allow the detection of biogas leakages and spots suitable for the gas extraction. Close-range aerial infrared thermography is an innovative approach able to identify thermal anomalies with a good resolution over a large region of the landfill surface. A simple procedure to deduce the biogas flow rate emerging from the soil into the atmosphere, based on infrared thermography measurements, is presented. The approach has been applied to a case study concerning a large landfill located in Genoa (Italy). Aerial infrared photographs taken during different days and seasons showed the presence of thermal anomalies over regions along the peripheral boundary of the landfill still not interested in biogas extraction.

  15. Removal of halogenated organic compounds in landfill gas by top covers containing zero-valent iron

    DEFF Research Database (Denmark)

    Scheutz, Charlotte; Winther, K.; Kjeldsen, Peter

    2000-01-01

    Transformation of gaseous CCl3F and CCl4 by zero-valent iron was studied in systems unsaturated with water under anaerobic conditionssin an N2 gas and in a landfill gas atmosphere. The transformation was studied in batch as well as flow-through column tests. In both systems, the transformation...... process of the compounds was pseudo-firstorder. Transformation rate constants, referring to the water phase and normalized to 1 m2 iron surface/mL, of up to 1100 mL m-2 h-1 (batch) and 200 mL m-2 h-1 (flowthrough) were found. The transformation was strongly dependent on pH and the presence of oxygen....... During continuous aerobic conditions, the transformation of CCl3F decreased toward zero. Model calculations show that use of zero-valent iron in landfill top covers is a potential treatment technology for emission reduction of halogenated trace compounds from landfills....

  16. Effectiveness of compacted soil liner as a gas barrier layer in the landfill final cover system.

    Science.gov (United States)

    Moon, Seheum; Nam, Kyoungphile; Kim, Jae Young; Hwan, Shim Kyu; Chung, Moonkyung

    2008-01-01

    A compacted soil liner (CSL) has been widely used as a single barrier layer or a part of composite barrier layer in the landfill final cover system to prevent water infiltration into solid wastes for its acceptable hydraulic permeability. This study was conducted to test whether the CSL was also effective in prohibiting landfill gas emissions. For this purpose, three different compaction methods (i.e., reduced, standard, and modified Proctor methods) were used to prepare the soil specimens, with nitrogen as gas, and with water and heptane as liquid permeants. Measured gas permeability ranged from 2.03 x 10(-10) to 4.96 x 10(-9) cm(2), which was a magnitude of two or three orders greater than hydraulic permeability (9.60 x 10(-13) to 1.05 x 10(-11) cm(2)). The difference between gas and hydraulic permeabilities can be explained by gas slippage, which makes gas more permeable, and by soil-water interaction, which impedes water flow and then makes water less permeable. This explanation was also supported by the result that a liquid permeability measured with heptane as a non-polar liquid was similar to the intrinsic gas permeability. The data demonstrate that hydraulic requirement for the CSL is not enough to control the gas emissions from a landfill.

  17. Development of an innovative uav-mountd screening tool for landfill gas emisiions

    DEFF Research Database (Denmark)

    Fjelsted, L.; Thomasen, T. B.; Valbjørn, I. L.

    2015-01-01

    Identification of landfill gas emission hot spots are potentially a very time consuming process, and the use of an Unmanned Aerial Vehicle (UAV) based screening tool could be an effective investigation strategy. In this study, the potential use of a long-wave thermal infrared camera...

  18. Development of an innovative uav-mounted screening tool for landfill gas emissions

    DEFF Research Database (Denmark)

    Fjelsted, Lotte; Thomasen, T. B.; Valbjørn, I. L.

    2015-01-01

    Identification of landfill gas emission hot spots are potentially a very time consuming process, and the use of an Unmanned Aerial Vehicle (UAV) based screening tool could be an effective investigation strategy. In this study, the potential use of a long-wave thermal infrared camera...

  19. Lateral gas transport in soil adjacent to an old landfill: factors governing emissions and methane oxidation

    DEFF Research Database (Denmark)

    Christophersen, Mette; Kjeldsen, Peter; Holst, Helle

    2001-01-01

    Field investigations of lateral gas transport and subsequent emissions in soil adjacent to an old landfill in Denmark have been conducted during a one-year period. A significant seasonal variation in the emissions with high carbon dioxide and low methane fluxes in the summer (May to October...

  20. DEMONSTRATION OF FUEL CELLS TO RECOVER ENERGY FROM LANDFILL GAS - PHASE I FINAL REPORT: CONCEPTUAL STUDY

    Science.gov (United States)

    The report discusses results of a conceptual design, cost, and evaluation study of energy recovery from landfill gas using a commercial phosphoric acid fuel cell power plant. The conceptual design of the fuel cell energy recovery system is described, and its economic and environm...

  1. Transport and reaction processes affecting the attenuation of landfill gas in cover soils

    DEFF Research Database (Denmark)

    Molins, S.; Mayer, K.U.; Scheutz, Charlotte

    2008-01-01

    of methane, chlorofluorocarbons, and hydrochlorofluorocarbons to the atmosphere. This study was conducted to investigate the effect of oxidation reactions on the overall gas transport regime and to evaluate, the contributions of various gas transport processes on methane attenuation in landfill cover soils....... For this purpose, a reactive transport model that includes advection and the Dusty Gas Model for simulation of multicomponent gas diffusion was used. The simulations are constrained by data from a series of counter-gradient laboratory experiments. Diffusion typically accounts for over 99% of methane emission....... Simulations suggest that production of water or accumulation of exopolymeric substances due to microbially mediated methane oxidation can significantly reduce diffusive fluxes. Assuming a constant rate of methane production within a landfill, reduction of the diffusive transport properties, primarily due...

  2. Well-to-Wheels analysis of landfill gas-based pathways and their addition to the GREET model.

    Energy Technology Data Exchange (ETDEWEB)

    Mintz, M.; Han, J.; Wang, M.; Saricks, C.; Energy Systems

    2010-06-30

    Today, approximately 300 million standard cubic ft/day (mmscfd) of natural gas and 1600 MW of electricity are produced from the decomposition of organic waste at 519 U.S. landfills (EPA 2010a). Since landfill gas (LFG) is a renewable resource, this energy is considered renewable. When used as a vehicle fuel, compressed natural gas (CNG) produced from LFG consumes up to 185,000 Btu of fossil fuel and generates from 1.5 to 18.4 kg of carbon dioxide-equivalent (CO{sub 2}e) emissions per million Btu of fuel on a 'well-to-wheel' (WTW) basis. This compares with approximately 1.1 million Btu and 78.2 kg of CO{sub 2}e per million Btu for CNG from fossil natural gas and 1.2 million Btu and 97.5 kg of CO{sub 2}e per million Btu for petroleum gasoline. Because of the additional energy required for liquefaction, LFG-based liquefied natural gas (LNG) requires more fossil fuel (222,000-227,000 Btu/million Btu WTW) and generates more GHG emissions (approximately 22 kg CO{sub 2}e /MM Btu WTW) if grid electricity is used for the liquefaction process. However, if some of the LFG is used to generate electricity for gas cleanup and liquefaction (or compression, in the case of CNG), vehicle fuel produced from LFG can have no fossil fuel input and only minimal GHG emissions (1.5-7.7 kg CO{sub 2}e /MM Btu) on a WTW basis. Thus, LFG-based natural gas can be one of the lowest GHG-emitting fuels for light- or heavy-duty vehicles. This report discusses the size and scope of biomethane resources from landfills and the pathways by which those resources can be turned into and utilized as vehicle fuel. It includes characterizations of the LFG stream and the processes used to convert low-Btu LFG into high-Btu renewable natural gas (RNG); documents the conversion efficiencies and losses of those processes, the choice of processes modeled in GREET, and other assumptions used to construct GREET pathways; and presents GREET results by pathway stage. GREET estimates of well-to-pump (WTP

  3. LCA and economic evaluation of landfill leachate and gas technologies

    DEFF Research Database (Denmark)

    Damgaard, Anders; Manfredi, Simone; Merrild, Hanna Kristina

    2011-01-01

    improvements for most impact categories. Global warming went from an impact of 0.1 person equivalent (PE) for the dump to −0.05 PE for the best design. Similar improvements were found for photochemical ozone formation (0.02 PE to 0.002 PE) and stratospheric ozone formation (0.04 PE to 0.001 PE).For the toxic...... through emissions of treated wastewater to surface waters.The largest environmental improvement with regard to the direct cost of the landfill was the capping and leachate treatment system. The capping, though very cheap to establish, gave a huge benefit in lowered impacts, the leachate collection system...

  4. Field-scale treatment of landfill gas with a passive methane oxidizing biofilter

    Energy Technology Data Exchange (ETDEWEB)

    Philopoulos, A. [Alberta Univ., Edmonton, AB (Canada). Dept. of Civil and Environmental Engineering; Felske, C. [Alberta Research Council, Edmonton, AB (Canada); McCartney, D. [Alberta Univ., Edmonton, AB (Canada). Dept. of Civil and Environmental Engineering, Natural Resources Engineering Facility

    2008-09-15

    Municipal solid waste (MSW) landfills produce methane (CH{sub 4}) and carbon dioxide (CO{sub 2}) as a result of the anaerobic biodegradation of organic fractions of waste. This paper provided details of field tests conducted to test 2 approaches that addressed the issue of gases produced at a landfill in Alberta. A CH{sub 4} oxidation layer was applied to replace intermediate and final landfill covers. Landfill gas (LFG) was then trapped using 3 biogenic CH{sub 4} oxidizing biofilters. Mature yard waste was used as a biofilter medium. The LFG was trapped by the liner, accumulated in a collection system, and then passed through the biofilter medium. The study was conducted over a period of 10 months. Results of the study showed that the integration of the biofilter into the landfill cover showed promising results. Low surface emissions were observed in 6 out of 8 monitoring events at 2 of the sites. Low influent LFG fluxes at the third site did not allow for full air sampling analyses to be conducted. 22 refs., 4 tabs., 8 figs.

  5. Landfills as a biorefinery to produce biomass and capture biogas.

    Science.gov (United States)

    Bolan, N S; Thangarajan, R; Seshadri, B; Jena, U; Das, K C; Wang, H; Naidu, R

    2013-05-01

    While landfilling provides a simple and economic means of waste disposal, it causes environmental impacts including leachate generation and greenhouse gas (GHG) emissions. With the introduction of gas recovery systems, landfills provide a potential source of methane (CH4) as a fuel source. Increasingly revegetation is practiced on traditionally managed landfill sites to mitigate environmental degradation, which also provides a source of biomass for energy production. Combustion of landfill gas for energy production contributes to GHG emission reduction mainly by preventing the release of CH4 into the atmosphere. Biomass from landfill sites can be converted to bioenergy through various processes including pyrolysis, liquefaction and gasification. This review provides a comprehensive overview on the role of landfills as a biorefinery site by focusing on the potential volumes of CH4 and biomass produced from landfills, the various methods of biomass energy conversion, and the opportunities and limitations of energy capture from landfills.

  6. TESTING OF FUEL CELLS TO RECOVER ENERGY FROM LANDFILL GAS: GROTON LANDFILL

    Science.gov (United States)

    The report summarizes the results of follow-on tests following a four-phase EPA program. The environmental impact of widespread use of this concept would be a significant reduction of global warming gas emissions (methane and carbon dioxide). The follow-on testing, conducted by N...

  7. Strategies to Optimize Microbially-Mediated Mitigation of Greenhouse Gas Emissions from Landfill Cover Soils

    Energy Technology Data Exchange (ETDEWEB)

    Jeremy Semrau; Sung-Woo Lee; Jeongdae Im; Sukhwan Yoon; Michael Barcelona

    2010-09-30

    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 CO{sub 2} credits is increased, can also be economically attractive.

  8. Characterization of trichloroethylene adsorption onto waste biocover soil in the presence of landfill gas.

    Science.gov (United States)

    He, Ruo; Su, Yao; Kong, Jiaoyan

    2015-09-15

    Waste biocover soils (WBS) have been demonstrated to have great potential in mitigating trichloroethylene (TCE) emission from landfills, due to the relatively high TCE-degrading capacity. In this study, the characteristics of TCE adsorption on WBS in the presence of the major landfill gas components (i.e., CH4 and CO2) were investigated in soil microcosms. The adsorption isotherm of TCE onto WBS was fitted well with linear model within the TCE concentrations of 7000 ppmv. The adsorption capacity of TCE onto WBS was affected by temperature, soil moisture content and particle size, of which, temperature was the dominant factor. The adsorption capacity of TCE onto the experimental materials increased with the increasing organic matter content. A significantly positive correlation was observed between the adsorption capacity of TCE and the organic matter content of experimental materials that had relatively higher organic content (r = 0.988, P = 0.044). To better understand WBS application in practice, response surface methodology was developed to predict TCE adsorption capacity and emissions through WBS in different landfills in China. These results indicated that WBS had high adsorption capacity of TCE in LFG and temperature should be paid more attention to manipulate WBS to reduce TCE emissions from landfills.

  9. Emission Control and Utilization of Landfill Gas in Ningbo Waste Landfill Site%宁波市垃圾填埋场填埋气体排放控制及利用研究

    Institute of Scientific and Technical Information of China (English)

    王斌

    2013-01-01

    Taking Ningbo city as an example,the treatment measures of unorganized emission of odor landfill gas from domestic waste sanitary landfill site were discussed,for instance,ordered collection and incineration-power generation.It could treat greenhouse gases such as CH4 effectively to make the pollutions control,and use waste heat to produce electricity.Thus it would achieve energy-saving and emission-reduction.%以宁波市为例,探讨了生活垃圾卫生填埋场产生的无组织排放的异味填埋气体有序收集及焚烧发电的处理措施,既有效处理了CH4等温室气体,使污染排放得到有效控制,又利用余热发电,实现节能减排.

  10. Landfilling: Environmental Issues

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Manfredi, Simone; Kjeldsen, Peter

    2011-01-01

    to air, soil and water caused by the processes stabilizing the waste in the landfill. The main factors controlling the actual environmental impacts from the landfilling are: the nature and amount of the waste landfilled, the geological and hydrological setting of the landfill, the landfill technology......, the extent and quality of the technical environmental protection measures introduced, the daily operation and the timescale. This chapter describes the main potential environmental impacts from landfills. The modern landfill is able to avoid most of these impacts. However, in the planning and design...... of landfills it is important to understand the potential environmental impacts, which must be avoided. The emissions of landfill gas and leachate causing most of the environmental risks are described in detail in the chapters addressing specific landfill types: Chapter 10.5 (mineral waste landfill), Chapter 10...

  11. Methane oxidation at low temperatures in soil exposed to landfill gas

    DEFF Research Database (Denmark)

    Christophersen, Mette; Linderød, L.; Jensen, Pernille Erland

    2000-01-01

    to gas recovery at smaller and older landfills in northern Europe. Equations have been developed that describe the dependency of temperature and soil moisture content for each soil. The oxidation rates depended significantly on the soils (and thereby organic matter content), temperature, and soil...... moisture content. Soil moisture was the most important factor. However, high Q(10) values indicate that temperature also was important. The four soils tested had optimum soil moisture content between 11 and 32%. At increasing organic matter content, both the optimal soil moisture content and the maximum...... cannot be extrapolated to soils exposed to high methane concentrations. Four sandy soils with different organic matter content (1-9% w/w) from two landfills in Denmark were investigated in batch experiments in the laboratory to determine the response of methane oxidation at low temperatures and different...

  12. Innovative landfill bioreactor systems for municipal solid waste treatment in East Africa aimed at optimal energy recovery and minimal greenhouse gas emissions

    NARCIS (Netherlands)

    Salukele, F.M.

    2013-01-01

    Landfilling is currently the dominant disposal method for municipal solid waste (MSW) in developing countries. Approximately 50% of the MSW generated in East Africa is disposed in landfills. Low costs and availability of land have made landfilling the most common waste management option in East Afri

  13. Innovative landfill bioreactor systems for municipal solid waste treatment in East Africa aimed at optimal energy recovery and minimal greenhouse gas emissions

    NARCIS (Netherlands)

    Salukele, F.M.

    2013-01-01

    Landfilling is currently the dominant disposal method for municipal solid waste (MSW) in developing countries. Approximately 50% of the MSW generated in East Africa is disposed in landfills. Low costs and availability of land have made landfilling the most common waste management option in East

  14. Adsorption characteristics of siloxanes in landfill gas by the adsorption equilibrium test

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Sangchul; Namkoong, Wan [Department of Environmental Engineering, Konkuk University, Hwayang-Dong, Gwangjin-Gu, Seoul 143-701 (Korea, Republic of); Kang, Jeong-Hee; Park, Jin-Kyu [Department of Environmental Engineering, Anyang University, Anyang 5-Dong, Manan-Gu, Anyang-Si, Gyeonggi-Do 430-714 (Korea, Republic of); Lee, Namhoon, E-mail: nhlee@anyang.ac.kr [Department of Environmental Engineering, Anyang University, Anyang 5-Dong, Manan-Gu, Anyang-Si, Gyeonggi-Do 430-714 (Korea, Republic of)

    2013-10-15

    Highlights: • Equilibrium test was attempted to evaluate adsorption characteristics of siloxane. • L2 had higher removal efficiency in carbon compared to noncarbon adsorbents. • Total adsorption capacity of siloxane was 300 mg/g by coal activated carbon. • Adsorption characteristics rely on size of siloxane molecule and adsorbent pore. • Conversion of siloxane was caused by adsorption of noncarbon adsorbents. - Abstract: Due to the increase in energy cost by constantly high oil prices and the obligation to reduce greenhouse effect gases, landfill gas is frequently used as an alternative energy source for producing heat and electricity. Most of landfill gas utility facilities, however, are experiencing problems controlling siloxanes from landfill gas as their catalytic oxidizers are becoming fouled by silicon dioxide dust. To evaluate adsorption characteristics of siloxanes, an adsorption equilibrium test was conducted and parameters in the Freundlich and Langmuir isotherms were analyzed. Coconut activated carbon (CA1), coal activated carbon (CA2), impregnated activated carbon (CA3), silicagel (NCA1), and activated alumina (NCA2) were used for the adsorption of the mixed siloxane which contained hexamethyldisiloxane (L2), octamethylcyclotetrasiloxane (D4), and decamethylcyclopentasiloxane (D5). L2 had higher removal efficiency in noncarbon adsorbents compared to carbon adsorbents. The application of Langmuir and Freundlich adsorption isotherm demonstrated that coconut based CA1 and CA3 provided higher adsorption capacity on L2. And CA2 and NCA1 provided higher adsorption capacity on D4 and D5. Based on the experimental results, L2, D4, and D5 were converted by adsorption and desorption in noncarbon adsorbents. Adsorption affinity of siloxane is considered to be affect by the pore size distribution of the adsorbents and by the molecular size of each siloxane.

  15. Removal of hydrogen sulfide gas and landfill leachate treatment using coal bottom ash.

    Science.gov (United States)

    Lin, C Y; Hesu, P H; Yang, D H

    2001-06-01

    Coal bottom ashes produced from three thermal power plants were used in column and batch experiments to investigate the adsorption capacity of the coal ash. Hydrogen sulfide and leachates collected from three sanitary landfill sites were used as adsorbate gas and solutions, respectively. Experimental results showed that coal bottom ash could remove H2S from waste gas or reduce the concentrations of various pollutants in the leachate. Each gram of bottom ash could remove up to 10.5 mg of H2S. In treating the landfill leachate, increasing ash dosage increased the removal efficiency but decreased the adsorption amount per unit mass of ash. For these tested ashes, the removal efficiencies of chemical oxygen demand (COD), NH3-N, total Kjeldhal nitrogen (TKN), P, Fe3+, Mn2+, and Zn2+ were 36.4-50, 24.2-39.4, 27.0-31.1, 82.2-92.9, 93.8-96.5, 93.7-95.4, and 80.5-82.2%, respectively; the highest adsorption capacities for those parameters were 3.5-5.6, 0.22-0.63, 0.36-0.45, 0.027-0.034, 0.050-0.053, 0.029-0.032, and 0.006 mg/g of bottom ash, respectively. The adsorption of pollutants in the leachate conformed to Freundlich's adsorption model.

  16. Landfill gas distribution at the base of passive methane oxidation biosystems: Transient state analysis of several configurations.

    Science.gov (United States)

    Ahoughalandari, Bahar; Cabral, Alexandre R

    2017-08-18

    The design process of passive methane oxidation biosystems needs to include design criteria that account for the effect of unsaturated hydraulic behavior on landfill gas migration, in particular, restrictions to landfill gas flow due to the capillary barrier effect, which can greatly affect methane oxidation rates. This paper reports the results of numerical simulations performed to assess the landfill gas flow behavior of several passive methane oxidation biosystems. The concepts of these biosystems were inspired by selected configurations found in the technical literature. We adopted the length of unrestricted gas migration (LUGM) as the main design criterion in this assessment. LUGM is defined as the length along the interface between the methane oxidation and gas distribution layers, where the pores of the methane oxidation layer material can be considered blocked for all practical purposes. High values of LUGM indicate that landfill gas can flow easily across this interface. Low values of LUGM indicate greater chances of having preferential upward flow and, consequently, finding hotspots on the surface. Deficient designs may result in the occurrence of hotspots. One of the designs evaluated included an alternative to a concept recently proposed where the interface between the methane oxidation and gas distribution layers was jagged (in the form of a see-saw). The idea behind this ingenious concept is to prevent blockage of air-filled pores in the upper areas of the jagged segments. The results of the simulations revealed the extent of the capability of the different scenarios to provide unrestricted and conveniently distributed upward landfill gas flow. They also stress the importance of incorporating an appropriate design criterion in the selection of the methane oxidation layer materials and the geometrical form of passive biosystems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Application of portable gas detector in point and scanning method to estimate spatial distribution of methane emission in landfill.

    Science.gov (United States)

    Lando, Asiyanthi Tabran; Nakayama, Hirofumi; Shimaoka, Takayuki

    2017-01-01

    Methane from landfills contributes to global warming and can pose an explosion hazard. To minimize these effects emissions must be monitored. This study proposed application of portable gas detector (PGD) in point and scanning measurements to estimate spatial distribution of methane emissions in landfills. The aims of this study were to discover the advantages and disadvantages of point and scanning methods in measuring methane concentrations, discover spatial distribution of methane emissions, cognize the correlation between ambient methane concentration and methane flux, and estimate methane flux and emissions in landfills. This study was carried out in Tamangapa landfill, Makassar city-Indonesia. Measurement areas were divided into basic and expanded area. In the point method, PGD was held one meter above the landfill surface, whereas scanning method used a PGD with a data logger mounted on a wire drawn between two poles. Point method was efficient in time, only needed one person and eight minutes in measuring 400m(2) areas, whereas scanning method could capture a lot of hot spots location and needed 20min. The results from basic area showed that ambient methane concentration and flux had a significant (pmethane emissions in the expanded area by using Kriging method. The average of estimated flux from scanning method was 71.2gm(-2)d(-1) higher than 38.3gm(-2)d(-1) from point method. Further, scanning method could capture the lower and higher value, which could be useful to evaluate and estimate the possible effects of the uncontrolled emissions in landfill.

  18. Assessment of soil-gas and groundwater contamination at the Gibson Road landfill, Fort Gordon, Georgia, 2011

    Science.gov (United States)

    Falls, W. Fred; Caldwell, Andral W.; Guimaraes, Wladmir G.; Ratliff, W. Hagan; Wellborn, John B.; Landmeyer, James E.

    2012-01-01

    Soil-gas and groundwater assessments were conducted at the Gibson Road landfill in 201 to provide screening-level environmental contamination data to supplement the data collected during previous environmental studies at the landfill. Passive samplers were used in both assessments to detect volatile and semivolatile organic compounds and polycyclic aromatic hydrocarbons in soil gas and groundwater. A total of 56 passive samplers were deployed in the soil in late July and early August for the soil-gas assessment. Total petroleum hydrocarbons (TPH) were detected at masses greater than the method detection level of 0.02 microgram in all samplers and masses greater than 2.0 micrograms in 13 samplers. Three samplers located between the landfill and a nearby wetland had TPH masses greater than 20 micrograms. Diesel was detected in 28 of the 56 soil-gas samplers. Undecane, tridecane, and pentadecane were detected, but undecane was the most common diesel compound with 23 detections. Only five detections exceeded a combined diesel mass of 0.10 microgram, including the highest mass of 0.27 microgram near the wetland. Toluene was detected in only five passive samplers, including masses of 0.65 microgram near the wetland and 0.85 microgram on the southwestern side of the landfill. The only other gasoline-related compound detected was octane in two samplers. Naphthalene was detected in two samplers in the gully near the landfill and two samplers along the southwestern side of the landfill, but had masses less than or equal to 0.02 microgram. Six samplers located southeast of the landfill had detections of chlorinated compounds, including one perchloroethene detections (0.04 microgram) and five chloroform detections (0.05 to0.08 microgram). Passive samplers were deployed and recovered on August 8, 2011, in nine monitoring wells along the southwestern, southeastern and northeastern sides of the landfill and down gradient from the eastern corner of the landfill. Six of the nine

  19. Assessment of soil-gas contamination at the 17th Street landfill, Fort Gordon, Georgia, 2011

    Science.gov (United States)

    Falls, W. Fred; Caldwell, Andral W.; Guimaraes, Wladmir G.; Ratliff, W. Hagan; Wellborn, John B.; Landmeyer, James E.

    2012-01-01

    Assessments of contaminants in soil gas were conducted in two study areas at Fort Gordon, Georgia, in July and August of 2011 to supplement environmental contaminant data for previous studies at the 17th Street landfill. The two study areas include northern and eastern parts of the 17th Street landfill and the adjacent wooded areas to the north and east of the landfill. These study areas were chosen because of their close proximity to the surface water in Wilkerson Lake and McCoys Creek. A total of 48 soil-gas samplers were deployed for the July 28 to August 3, 2011, assessment in the eastern study area. The assessment mostly identified detections of total petroleum hydrocarbons (TPH), and gasoline- and diesel-range compounds, but also identified the presence of chlorinated solvents in six samplers, chloroform in three samplers, 2-methyl naphthalene in one sampler, and trimethylbenzene in one sampler. The TPH masses exceeded 0.02 microgram (μg) in all 48 samplers and exceeded 0.9 μg in 24 samplers. Undecane, one of the three diesel-range compounds used to calculate the combined mass for diesel-range compounds, was detected in 17 samplers and is the second most commonly detected compound in the eastern study area, exceeded only by the number of TPH detections. Six samplers had detections of toluene, but other gasoline compounds were detected with toluene in three of the samplers, including detections of ethylbenzene, meta- and para-xylene, and octane. All detections of chlorinated organic compounds had soil-gas masses equal to or less than 0.08 μg, including three detections of trichloroethene, three detections of perchloroethene, three chloroform detections, one 1,4-dichlorobenzene detection, and one 1,1,2-trichloroethane detection. Three methylated compounds were detected in the eastern study area, but were detected at or below method detection levels. A total of 32 soil-gas samplers were deployed for the August 11–24, 2011, assessment in the northern study

  20. Measurements of methane emissions from landfills using mobile plume method with trace gas and cavity ring-down spectroscopy

    Science.gov (United States)

    Mønster, J.; Kjeldsen, P.; Scheutz, C.

    2012-04-01

    Methane is emitted to the atmosphere from both anthropogenic and natural sources. One of the major anthropogenic sources is methane produced by bacteria in anaerobic environments such as rice pads and landfills. Land filling has for many years been the preferred waste disposal method, resulting in a large methane production with a large contribution to the global increase in atmospheric green house gas concentration. Several steps have been taken to reduce the emission of methane from landfills. In order to validate the effect of these steps, a measurement method is needed to quantify methane emissions with a large spatial variation. One method is to use a highly sensitive and fast analytical method, capable of measuring the atmospheric concentration methane downwind from emission areas. Combined with down-wind measurements of a trace gas, emitted at a controlled mass flow rate, the methane emission can be calculated. This method is called the mobile plume method, as the whole plume is measured by doing several transects. In the current study a methane/acetylene analyzer with cavity ring-down spectroscopy detection (Picarro, G2203) was used to estimate methane from a number of Danish landfills. We measured at both active and closed landfills and investigated the difference in methane emission. At landfills where the emissions could have more than one origin, the source strength of the different emission areas was determined by accurate trace gas positioning and choosing appropriate wind speed and measurement distance. To choose these factors, we addressed the uncertainties and limitations of the method with respect to the configuration of the trace gas bottles and the distance between the emission area and the measurement points. Composting of organic material in large piles was done at several of the investigated landfills and where possible, the methane emission from this partly anaerobic digestion was measured as a separate emission.

  1. Evaluation of aerated biofilter systems for microbial methane oxidation of poor landfill gas.

    Science.gov (United States)

    Haubrichs, R; Widmann, R

    2006-01-01

    In the long-term, landfills are producing landfill gas (LFG) with low calorific values. Therefore, the utilization of LFG in combined heat and power plants (CHP) is limited to a certain period of time. A feasible method for LFG treatment is microbial CH(4) oxidation. Different materials were tested in actively aerated lab-scale bio-filter systems with a volume of 0.167 m(3). The required oxygen for the microbial CH(4) oxidation was provided through perforated probes, which distributed ambient air into the filter material. Three air input levels were installed along the height of the filter, each of them adjusted to a particular flow rate. During the tests, stable degradation rates of around 28 g/(m(3) h) in a fine-grained compost material were observed at a CH(4) inlet concentration of 30% over a period of 148 days. Compared with passive (not aerated) tests, the CH(4) oxidation rate increased by a factor of 5.5. Therefore, the enhancement of active aeration on the microbial CH(4) oxidation was confirmed. At a O(2)/CH(4) ratio of 2.5, nearly 100% of the CH(4) load was decomposed. By lowering the ratio from 2.5 to 2, the efficiency fell to values from 88% to 92%. By varying the distribution to the three air input levels, the CH(4) oxidation process was spread more evenly over the filter volume.

  2. In-Situ Quantification of Methanotrophic Activity in a Landfill Cover Soil Using Gas Push-Pull Tests

    Science.gov (United States)

    Gomez, K. E.; Gonzalez-Gil, G.; Schroth, M. H.; Zeyer, J.

    2007-12-01

    Landfills are both a major anthropogenic source and a sink for the greenhouse gas CH4. Methanogenic bacteria produce CH4 during the anaerobic digestion of landfill waste, whereas, methanotrophic bacteria consume CH4 as it is transported through a landfill cover soil. Methanotrophs are thought to be ubiquitous in soils, but typically exist in large numbers at oxic/anoxic interfaces, close to anaerobic methane sources but exposed to oxygen required for metabolism. Accurate in-situ quantification of the sink strength of methanotrophs in landfill cover soils is needed for global carbon balances and for local emissions mitigation strategies. We measured in-situ CH4 concentrations at 30, 60, and 100 cm depth at 18 evenly spaced locations across a landfill cover soil. Furthermore, we performed Gas Push-Pull Tests (GPPTs) to estimate in-situ rates of methanotrophic activity in the cover soil. The GPPT is a gas-tracer test in which a gas mixture containing CH4, O2, and non-reactive tracer gases is injected (pushed) into the soil followed by extraction (pull) from the same location. Quantification of CH4 oxidation rates is based upon comparison of the breakthrough curves of CH4 and tracer gases. We present the results of a series of GPPTs conducted at two locations in the cover soil to assess the feasibility and reproducibility of this technique to quantify methanotrophic activity. Additional GPPTs were performed with a methanotrophic inhibitor in the injection gas mixture to confirm the appropriate choice of tracers to quantify CH4 oxidation. Estimated CH4 oxidation rate constants indicate that the cover soil contains a highly active methanotrophic community.

  3. Auto generation plant of Artigas landfill (Bilbao, Spain); Planta de autogeneracion electrica del vertedero de Artigas (Bilbao)

    Energy Technology Data Exchange (ETDEWEB)

    Carreras, N.; Dorronsoro, J.L.

    1996-07-01

    The disposition of MSW in the landfill generates a mixture of gases or {sup b}iogas{sup ,} its primary content is methane (50-60%) which has a very important energetic value, that can be very useful. In this sense, the present work point out the characteristics of the auto generation electrical plant of Artigas landfill, just like the results of the analytical study of the past two years. In this project which was partly funded by the UE, have participated Excmo. Ayuntamiento de Bilbao, EVE and CIEMAT. (Author) 6 refs.

  4. Application of Vadose Zone Monitoring Technology for Characterization of Leachate Generation in Landfills

    Science.gov (United States)

    aharoni, imri; dahan, ofer

    2016-04-01

    Ground water contamination due to landfill leachate percolation is considered the most severe environmental threat related to municipal solid waste landfills. Natural waste degradation processes in landfills normally produce contaminated leachates up to decades after the waste has been buried. Studies have shown that understanding the mechanisms which govern attenuation processes and the fate of pollutants in the waste and in the underlying unsaturated zone is crucial for evaluation of environmental risks and selection of a restoration strategy. This work focuses on a closed landfill in the coastal plain of Israel that was active until 2002 without any lining infrastructure. A vadose zone monitoring system (VMS) that was implemented at the site enables continuous measurements across the waste body (15 m thick) and underlying sandy vadose zone (16 m thick). Data collected by the VMS included continuous measurements of water content as well as chemical composition of the leachates across the entire waste and vadose zone cross section. Results indicated that winter rain percolated through the waste, generating wetting waves which were observed across the waste and unsaturated sediment from land surface until groundwater at 31 m bls. Quick percolation and high fluxes were observed in spite of the clay cover that was implemented at the site as part of the rehabilitation scheme. The results show that the flow pattern is controlled by a preferential mechanism within the waste body. Specific sections showed rapid fluxes in response to rain events, while other sections remained unaffected. In the underlying sandy vadose zone the flow pattern exhibited characteristics of matrix flow. Yet, some sections received higher fluxes due to the uneven discharge of leachates from the overlying waste body. Water samples collected from the waste layer indicate production of highly polluted leachates over 14 years after the landfill was closed. The chemical composition within the waste

  5. Contact Group Landfill Gas: Report of the regional meetings on 9 November 1993 in Apeldoorn, Netherlands, and 11 November 1993 in Meteren, Netherlands. Contactgroep Stortgas: Verslag van de regionale bijeenkomsten op 9 november 1993 in Apeldoorn en 11 november 1993 in Meteren

    Energy Technology Data Exchange (ETDEWEB)

    1993-12-01

    By the Consultancy Centre Landfill Gas the Contact Group Landfill Gas was established for energy utilities, landfill gas managers and exploiters of landfill gas installations. The meetings held so far are reported. During the meetings lectures on the landfill gas potential in the Netherlands, on Waste Disposal Regulations, and on the formation of dioxins in the landfill gas combustion process were presented. Summaries of these lectures can be found in this report. Also reports are given of visits to landfill gas projects. The projects are briefly described. 4 figs., 1 tab.

  6. Greenhouse gas emissions from municipal solid waste management in Indian mega-cities: a case study of Chennai landfill sites.

    Science.gov (United States)

    Jha, Arvind K; Sharma, C; Singh, Nahar; Ramesh, R; Purvaja, R; Gupta, Prabhat K

    2008-03-01

    Municipal solid waste generation rate is over-riding the population growth rate in all mega-cities in India. Greenhouse gas emission inventory from landfills of Chennai has been generated by measuring the site specific emission factors in conjunction with relevant activity data as well as using the IPCC methodologies for CH4 inventory preparation. In Chennai, emission flux ranged from 1.0 to 23.5mg CH4m(-2)h(-1), 6 to 460microg N2Om(-2)h(-1) and 39 to 906mg CO2m(2)h(-1) at Kodungaiyur and 0.9 to 433mg CH4m(-2)h(-1), 2.7 to 1200microg N2Om(-2)h(-1) and 12.3 to 964.4mg CO2m(-2)h(-1) at Perungudi. CH4 emission estimates were found to be about 0.12Gg in Chennai from municipal solid waste management for the year 2000 which is lower than the value computed using IPCC, 1996 [IPCC, 1996. Report of the 12th session of the intergovernmental panel of climate change, Mexico City, 1996] methodologies.

  7. Use of gas push-pull tests for the measurement of methane oxidation in different landfill cover soils.

    Science.gov (United States)

    Streese-Kleeberg, Jan; Rachor, Ingke; Gebert, Julia; Stegmann, Rainer

    2011-05-01

    In order to optimise methane oxidation in landfill cover soils, it is important to be able to accurately quantify the amount of methane oxidised. This research considers the gas push-pull test (GPPT) as a possible method to quantify oxidation rates in situ. During a GPPT, a gas mixture consisting of one or more reactive gases (e.g., CH(4), O(2)) and one or more conservative tracers (e.g., argon), is injected into the soil. Following this, the mixture of injected gas and soil air is extracted from the same location and periodically sampled. The kinetic parameters for the biological oxidation taking place in the soil can be derived from the differences in the breakthrough curves. The original method of Urmann et al. (2005) was optimised for application in landfill cover soils and modified to reduce the analytical effort required. Optimised parameters included the flow rate during the injection phase and the duration of the experiment. 50 GPPTs have been conducted at different landfills in Germany during different seasons. Generally, methane oxidation rates ranged between 0 and 150 g m(soil air)(-3)h(-1). At one location, rates up to 440 g m(soil air)(-3)h(-1) were measured under particularly favourable conditions. The method is simple in operation and does not require expensive equipment besides standard laboratory gas chromatographs.

  8. Assessment of soil-gas, seep, and soil contamination at the North Range Road Landfill, Fort Gordon, Georgia, 2008-2009

    Science.gov (United States)

    Landmeyer, James E.; Falls, W. Fred; Ratliff, W. Hagan; Wellborn, John B.

    2011-01-01

    Soil gas, seeps, and soil were assessed for contaminants at the North Range Road Landfill at Fort Gordon, Georgia, from October 2008 to September 2009. The assessment included delineating organic contaminants present in soil-gas samples beneath the area estimated to be the landfill and in water samples collected from three seeps at the base of the landfill. Inorganic contaminants were determined in three seep samples and in soil samples. This assessment was conducted to provide environmental contamination data to Fort Gordon pursuant to requirements for the Resource Conservation and Recovery Act Part B Hazardous Waste Permit process.

  9. A simple model for the distribution and fate of organic chemicals in a landfill: MOCLA

    DEFF Research Database (Denmark)

    Kjeldsen, Peter; Christensen, Thomas Højlund

    2001-01-01

    of degradation and transformation in the landfill. Local equilibrium is assumed for the distribution of the chemicals in the landfill as expressed by Henry’s Law for the leachate-gas interface, and by the linear partition coefficient based on the waste solid organic carbon content for the waste......A simple mathematical model (MOCLA: Model for Organic Chemicals in Landfills) is presented, describing the distribution of organic chemicals between leachate, gas and solid waste. The model also predicts the fate of the chemicals in terms of emissions with leachate and landfill gas and in terms......-leachate interface. Degradation of the chemicals is expressed as a first order reaction. Annual specific leachate and gas generation data in combination with data on landfill area and volume allow for prediction of main emission routes. Model simulations involving two landfill scenarios for a number of chemicals...

  10. Potential production of electricity from biogas generated in a sanitary landfill

    Directory of Open Access Journals (Sweden)

    Quetzalli Aguilar-Virgen

    2011-08-01

    Full Text Available Energy forms the cornerstone of almost every economic, social and cultural sector in modern societies. Energy is regarded as an irreplaceable ingredient in such societies’ industrial development. The aim of this research was to estimate the generation of biogas in the city of Ensenada’s sanitary landfill to ascertain the amount of energy which could be generated from the solid waste being disposed of. Biogas estimates were conducted in two stages: a waste characterisation study followed by implementing the regulations proposed by SCS Engineers (SCS Engineers, 2009 regarding the Mexican biogas model (version 2.0. The results showed that a large quantity of organic matter (around 70% is a key element in anaerobic degradation of waste. As to energy generation, it is believed that a full 1.90 MW capacity will be reached in 2019. Such energy could increase Ensenada’s current electricity generation capacity by 3.46% and provide 60% of the energy needed for street lighting, thereby leading to USD $1.423 million in savings.

  11. The estimation of methane emissions from landfills with different cover systems

    Science.gov (United States)

    Park, S.; Lee, K.; Sung, K.

    2006-12-01

    Methane is a very potent greenhouse gas, second only to CO2 as an anthropogenic contributor to global warming. Landfills are important anthropogenic source in the CH4 emissions. Microbially mediated CH4 oxidation in landfills with conventional soil covers can serve as an efficient biological sink. Methane from modern sanitary landfills equipped with composite covers and gas collection system is vented directly to the atmosphere, except for some of the largest landfills at which it is collected and burned. However, previous laboratory research has shown that biofilters have the potential to reduce CH4 emissions from landfills with modern composite covers. In this study a CH4 emission model was developed. The model used the calculated CH4 oxidation rates to estimate CH4 emissions from landfills constructed with conventional soil covers, modern composite covers, and modern composite covers plus biofilters. According to the CH4 emission rates predicted by CH4 emission model, it was estimated that 90% of the generated CH4 was emitted to the atmosphere for landfills with modern composite cover. For landfills with modern composite cover plus biofilters, an average of only 9% of the generated CH4 was estimated to be emitted. For landfills with conventional covers, an average of 83% of the generated CH4 was estimated to be emitted. By comparing the CH4 emission rates from three different landfill types, the use of a properly managed biofilter should be an effective technique to reduce CH4 emissions from landfills.

  12. Estimate Of The Decay Rate Constant of Hydrogen Sulfide Generation From Landfilled Drywall

    Science.gov (United States)

    Research was conducted to investigate the impact of particle size on H2S gas emissions and estimate a decay rate constant for H2S gas generation from the anaerobic decomposition of drywall. Three different particle sizes of regular drywall and one particle size of paperless drywa...

  13. Technical potential of electricity production from municipal solid waste disposed in the biggest cities in Brazil: landfill gas, biogas and thermal treatment.

    Science.gov (United States)

    de Souza, Samuel Nm; Horttanainen, Mika; Antonelli, Jhonatas; Klaus, Otávia; Lindino, Cleber A; Nogueira, Carlos Ec

    2014-10-01

    This article presents an analysis of possibilities for electrical energy production by using municipal solid waste disposed in the biggest Brazilian cities. Currently, the municipal solid waste in Brazil is collected and disposed of at landfills, but there are also other technologies, which in addition to dealing with the garbage can also provide benefits in terms of energy provision. The following scenarios were studied in this work: electricity production from landfill gas (reference scenario); incineration of all municipal solid waste; anaerobic digestion of organic waste and incineration of refuse-derived fuel fractions after being separated in separation plants. According to this study, the biggest cities in Brazil generate about 18.9 million tonnes of municipal solid waste per year (2011), of which 51.5% is biogenic matter. The overall domestic consumption of electricity is 480,120 GWh y(-1) in Brazil and the municipal solid waste incineration in the 16 largest cities in the country could replace 1.8% of it using incinerators. The city of São Paulo could produce 637 GWh y(-1) with landfill gas, 2368 GWh y(-1) with incineration of municipal solid waste and 1177 GWh y(-1) with incineration of refuse-derived fuel. The latter two scenarios could replace 27% and 13.5% of the residential electrical energy consumption in the city. This shows that thermal treatment might be a viable option of waste-to-energy in Brazil. © The Author(s) 2014.

  14. Cryogenic Heat-Exchanger Design for Freeze-out Removal of Carbon Dioxide from Landfill Gas

    Science.gov (United States)

    Chang, Ho-Myung; Chung, Myung Jin; Park, Seong Bum

    A cryogenic heat exchanger to remove carbon dioxide from landfill gas (LFG) is proposed and designed for applications to LNG production in distributed-scale. Since the major components of LFG are methane and carbon dioxide, CO2 removal is a significant pre-process in the liquefaction systems. A new and simple approach is proposed to directly remove carbon dioxide as frost on the surface wall along the cooling passage in a liquefying heat exchanger and to install two identical heat exchangers in parallel for alternative switching. As a first step of feasibility study, combined heat and mass transfer analysis is performed on the freeze-out process of CO2 in a counterflow heat exchanger, where CH4-CO2 mixture is cooled below its frost temperature in thermal contact with cold refrigerant. Engineering correlations for the analogy of heat and mass transfer are incorporated into numerical heat exchanger analysis with detailed fluid properties. The developed analytical model is used to estimate the distribution of CO2 accumulation and the required heat exchanger size with latent thermal load for the cryogenic CO2 removal in various operating conditions.

  15. Methane Emissions from Landfill: Isotopic Evidence for Low Percentage of Oxidation from Gas Wells, Active and Closed Cells

    Science.gov (United States)

    Lowry, David; Fisher, Rebecca; Zazzeri, Giulia; al-Shalaan, Aalia; France, James; Lanoisellé, Mathias; Nisbet, Euan

    2017-04-01

    Large landfill sites remain a significant source of methane emissions in developed and developing countries, with a global estimated flux of 29 Tg / yr in the EDGAR 2008 database. This is significantly lower than 20 years ago due to the introduction of gas extraction systems, but active cells still emit significant amounts of methane before the gas is ready for extraction. Historically the methane was either passively oxidized through topsoil layers or flared. Oxidation is still the primary method of methane removal in many countries, and covered, remediated cells across the world continue to emit small quantities of methane. The isotopic signatures of methane from landfill gas wells, and that emitted from active and closed cells have been characterized for more than 20 UK landfills since 2011, with more recent work in Kuwait and Hong Kong. Since 2013 the emission plumes have been identified by a mobile measurement system (Zazzeri et al., 2015). Emissions in all 3 countries have a characteristic δ13C signature of -58 ± 3 ‰ dominated by emissions from the active cells, despite the hot, dry conditions of Kuwait and the hot, humid conditions of Hong Kong. Gas well samples define a similar range. Surface emissions from closed cells and closed landfills are mostly in the range -56 to -52 ‰Ṫhese are much more depleted values than those observed in the 1990s (up to -35 ) when soil oxidation was the dominant mechanism of methane removal. Calculations using isotopic signatures of the amount of methane oxidised in these closed areas before emission to atmosphere range from 5 to 15%, but average less than 10%, and are too small to calculate from the high-emitting active cells. Compared to other major methane sources, landfills have the most consistent isotopic signature globally, and are distinct from the more 13C-enriched natural gas, combustion and biomass burning sources. Zazzeri, G. et al. (2015) Plume mapping and isotopic characterization of anthropogenic methane

  16. LANDFILL OPERATION FOR CARBON SEQUESTRATION AND MAXIMUM METHANE EMISSION CONTROL

    Energy Technology Data Exchange (ETDEWEB)

    Don Augenstein; Ramin Yazdani; Rick Moore; Michelle Byars; Jeff Kieffer; Professor Morton Barlaz; Rinav Mehta

    2000-02-26

    Controlled landfilling is an approach to manage solid waste landfills, so as to rapidly complete methane generation, while maximizing gas capture and minimizing the usual emissions of methane to the atmosphere. With controlled landfilling, methane generation is accelerated to more rapid and earlier completion to full potential by improving conditions (principally moisture, but also temperature) to optimize biological processes occurring within the landfill. Gas is contained through use of surface membrane cover. Gas is captured via porous layers, under the cover, operated at slight vacuum. A field demonstration project has been ongoing under NETL sponsorship for the past several years near Davis, CA. Results have been extremely encouraging. Two major benefits of the technology are reduction of landfill methane emissions to minuscule levels, and the recovery of greater amounts of landfill methane energy in much shorter times, more predictably, than with conventional landfill practice. With the large amount of US landfill methane generated, and greenhouse potency of methane, better landfill methane control can play a substantial role both in reduction of US greenhouse gas emissions and in US renewable energy. The work described in this report, to demonstrate and advance this technology, has used two demonstration-scale cells of size (8000 metric tons [tonnes]), sufficient to replicate many heat and compaction characteristics of larger ''full-scale'' landfills. An enhanced demonstration cell has received moisture supplementation to field capacity. This is the maximum moisture waste can hold while still limiting liquid drainage rate to minimal and safely manageable levels. The enhanced landfill module was compared to a parallel control landfill module receiving no moisture additions. Gas recovery has continued for a period of over 4 years. It is quite encouraging that the enhanced cell methane recovery has been close to 10-fold that experienced with

  17. Methane elimination methods on landfills

    OpenAIRE

    Ponikvar, Martin

    2008-01-01

    Increase in substance and energy exploitation from waste which reduces the greenhouse gas emissions are one of the main goals of environmental protection. Slovenian legislation defines that in case captured landfill gas cannot be used for energy acquisition, incineration on the landfill itself or some other equivalent procedure must be used to prevent gas emissions into the air. The graduation thesis is based on existing municipal landfill Volče where suitable gas elimination is yet to be arr...

  18. Emission model for landfills with mechanically-biologically pretreated waste, with the emphasis on modelling the gas balance; Emissionsprognosemodell fuer Deponien mit mechanisch-biologisch vorbehandelten Abfaellen - Schwerpunkt: Modellierung des Gashaushaltes

    Energy Technology Data Exchange (ETDEWEB)

    Danhamer, H.

    2001-07-01

    The objective of this work was to determine influence factors on processes going on in landfills with mechanically-biologically pretreated waste (MBP-landfills) in order to predict emissions. For this purpose a computer based model has been developed. The model allows to simulate the gas, water and heat balance as well as settlement processes and was called DESIM2005 (version MB). It is based on theoretical modeling approaches as well as data from lab and reactor experiments. The main focus of model application was to determine factors influencing the gas phase and the emissions of landfill gas and methane during operation and aftercare of MBP-landfills. By performing simulations the effects of changing parameters for the processes gas transport and biological degradation as well as the effects of different qualities in waste pretreatment and of varying landfill operation techniques were investigated. Possibilities for increasing the environmental sustainability of landfills containing mechanically-biologically pretreated waste were shown. (orig.)

  19. Assessment of soil-gas, soil, and water contamination at the former hospital landfill, Fort Gordon, Georgia, 2009-2010

    Science.gov (United States)

    Falls, Fred W.; Caldwell, Andral W.; Guimaraes, Wladmir B.; Ratliff, W. Hagan; Wellborn, John B.; Landmeyer, James E.

    2011-01-01

    Soil gas, soil, and water were assessed for organic and inorganic constituents at the former hospital landfill located in a 75-acre study area near the Dwight D. Eisenhower Army Medical Center, Fort Gordon, Georgia, from April to September 2010. Passive soil-gas samplers were analyzed to evaluate organic constituents in the hyporheic zone of a creek adjacent to the landfill and soil gas within the estimated boundaries of the former landfill. Soil and water samples were analyzed to evaluate inorganic constituents in soil samples, and organic and inorganic constituents in the surface water of a creek adjacent to the landfill, respectively. This assessment was conducted to provide environmental constituent data to Fort Gordon pursuant to requirements of the Resource Conservation and Recovery Act Part B Hazardous Waste Permit process. Results from the hyporheic-zone assessment in the unnamed tributary adjacent to the study area indicated that total petroleum hydrocarbons and octane were the most frequently detected organic compounds in groundwater beneath the creek bed. The highest concentrations for these compounds were detected in the upstream samplers of the hyporheic-zone study area. The effort to delineate landfill activity in the study area focused on the western 14 acres of the 75-acre study area where the hyporheic-zone study identified the highest concentrations of organic compounds. This also is the part of the study area where a debris field also was identified in the southern part of the 14 acres. The southern part of this 14-acre study area, including the debris field, is steeper and not as heavily wooded, compared to the central and northern parts. Fifty-two soil-gas samplers were used for the July 2010 soil-gas survey in the 14-acre study area and mostly detected total petroleum hydrocarbons, and gasoline and diesel compounds. The highest soil-gas masses for total petroleum hydrocarbons, diesel compounds, and the only valid detection of perchloroethene

  20. ENGINEERING ASPECTS OF LANDFILLING MUNICIPAL SOLID WASTE

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Sanitary landfilling is the most important method of municipalsolid waste disposal in China. Landfill sites are always set up in mountain valley, on plain or beside seashore. A complete landfill consists of base system, cover system, and leachate collection and gas extraction system. This paper reviews the state-of-the-art landfilling technology in China and collection discusses research projects for engineers.

  1. The Chemistry of Flammable Gas Generation

    Energy Technology Data Exchange (ETDEWEB)

    ZACH, J.J.

    2000-10-30

    The document collects information from field instrumentation, laboratory tests, and analytical models to provide a single source of information on the chemistry of flammable gas generation at the Hanford Site. It considers the 3 mechanisms of formation: radiolysis, chemical reactions, and thermal generation. An assessment of the current models for gas generation is then performed. The results are that the various phenomena are reasonably understood and modeled compared to field data.

  2. Pilot scale evaluation of the BABIU process--upgrading of landfill gas or biogas with the use of MSWI bottom ash.

    Science.gov (United States)

    Mostbauer, P; Lombardi, L; Olivieri, T; Lenz, S

    2014-01-01

    Biogas or landfill gas can be converted to a high-grade gas rich in methane with the use of municipal solid waste incineration bottom ash as a reactant for fixation of CO2 and H2S. In order to verify results previously obtained at a laboratory scale with 65-90 kg of bottom ash (BA), several test runs were performed at a pilot scale, using 500-1000 kg of bottom ash and up to 9.2 Nm(3)/h real landfill gas from a landfill in the Tuscany region (Italy). The input flow rate was altered. The best process performance was observed at a input flow rate of 3.7 Nm(3)/(htBA). At this flow rate, the removal efficiencies for H2S were approximately 99.5-99%. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. USING LANDFILL GAS IN FUEL CELLS - A STEP CLOSER TO COMMERICAL REALITY

    Science.gov (United States)

    The article discusses Phase II and Phase III results of a U.S. EPA program underway at International Fuel Cells Corporation. The program involves controlling methane emissions from landfills using a fuel cell. The fuel cell would reduce air emissions affecting global warming, aci...

  4. Microbial Methane Oxidation Processes and Technologies for Mitigation of Landfill Gas Emissions

    Science.gov (United States)

    The aim of this paper is to review the present knowledge regarding the microbial methane oxidation in natural or engineered landfill environments with focus on process understanding, engineering experiences and modeling. This review includes seven sections. First, the methane oxidation is put in con...

  5. Lateral gas transport in soil adjacent to an old landfill: factors governing emissions and methane oxidation

    DEFF Research Database (Denmark)

    Christophersen, Mette; Kjeldsen, Peter; Holst, Helle;

    2001-01-01

    influence on the fluxes, as did the distance from the landfill border, temperature, barometric pressure and the pressure gradient. Statistical analyses proved that soil moisture described the largest part of the variation. No methane at all emitted during the summer. Calculations and isotope analyses showed...

  6. Landfilling of waste: accounting of greenhouse gases and global warming contributions.

    Science.gov (United States)

    Manfredi, Simone; Tonini, Davide; Christensen, Thomas H; Scharff, Heijo

    2009-11-01

    Accounting of greenhouse gas (GHG) emissions from waste landfilling is summarized with the focus on processes and technical data for a number of different landfilling technologies: open dump (which was included as the worst-case-scenario), conventional landfills with flares and with energy recovery, and landfills receiving low-organic-carbon waste. The results showed that direct emissions of GHG from the landfill systems (primarily dispersive release of methane) are the major contributions to the GHG accounting, up to about 1000 kg CO(2)-eq. tonne( -1) for the open dump, 300 kg CO(2)-eq. tonne( -1) for conventional landfilling of mixed waste and 70 kg CO(2)-eq. tonne(-1) for low-organic-carbon waste landfills. The load caused by indirect, upstream emissions from provision of energy and materials to the landfill was low, here estimated to be up to 16 kg CO(2)-eq. tonne(-1). On the other hand, utilization of landfill gas for electricity generation contributed to major savings, in most cases, corresponding to about half of the load caused by direct GHG emission from the landfill. However, this saving can vary significantly depending on what the generated electricity substitutes for. Significant amounts of biogenic carbon may still be stored within the landfill body after 100 years, which here is counted as a saved GHG emission. With respect to landfilling of mixed waste with energy recovery, the net, average GHG accounting ranged from about -70 to 30 kg CO(2)-eq. tonne(- 1), obtained by summing the direct and indirect (upstream and downstream) emissions and accounting for stored biogenic carbon as a saving. However, if binding of biogenic carbon was not accounted for, the overall GHG load would be in the range of 60 to 300 kg CO(2)-eq. tonne( -1). This paper clearly shows that electricity generation as well as accounting of stored biogenic carbon are crucial to the accounting of GHG of waste landfilling.

  7. 2D Time-lapse Resistivity Monitoring of an Organic Produced Gas Plume in a Landfill using ERT.

    Science.gov (United States)

    Amaral, N. D.; Mendonça, C. A.; Doherty, R.

    2014-12-01

    This project has the objective to study a landfill located on the margins of Tietê River, in São Paulo, Brazil, using the electroresistivity tomography method (ERT). Due to huge organic matter concentrations in the São Paulo Basin quaternary sediments, there is subsurface depth related biogas accumulation (CH4 and CO2), induced by anaerobic degradation of the organic matter. 2D resistivity sections were obtained from a test area since March 2012, a total of 7 databases, being the last one dated from October 2013. The studied line has the length of 56m, the electrode interval is of 2m. In addition, there are two boreholes along the line (one with 3 electrodes and the other one with 2) in order to improve data quality and precision. The boreholes also have a multi-level sampling system that indicates the fluid (gas or water) presence in relation to depth. With our results it was possible to map the gas plume position and its area of extension in the sections as it is a positive resistivity anomaly, with the gas level having approximately 5m depth. With the time-lapse analysis (Matlab script) between the obtained 2D resistivity sections from the site, it was possible to map how the biogas volume and position change in the landfill in relation to time. Our preliminary results show a preferential gas pathway through the subsurface studied area. A consistent relation between the gas depth and obtained microbiological data from archea and bacteria population was also observed.

  8. Using landfill gas as the primary fuel for a 200 WTPD thermal dryer[Held jointly with the 4. Canadian organic residuals and biosolids managment conference

    Energy Technology Data Exchange (ETDEWEB)

    Shulmister, D. [Manattee County, Manatee, FL (United States). Wastewater Division; Monroe, A. [McKim and Creed, Cary, NC (United States)

    2007-07-01

    Although there is no evidence of health problems, there is a growing opposition to class B land application of biosolids in many localities in the United States, resulting in less sites available to dispose of class B biosolids. Manatee County, located on the West Coast of Florida, decided to implement thermal drying of its biosolids. This produced a class A pellet that could be used without restriction as a fertilizer or soil amendment. The dryer will be located at the county's southeast water reclamation facility, adjacent to the county's Lena Road landfill. The methane gas from the landfill will be used as the primary fuel for the dryer. This paper presented how Manatee County, Florida decided to meet its long term biosolids handling and disposal needs. The paper provided background information on Manatee County, Florida. It discussed the reasons for the dryer technology selection, location of the dryer, sizing criteria as well as listing the components of the dryer. The paper also discussed dryer procurement. Other topics that were presented included fuel requirements and an analysis of landfill gas. The County expects to save approximately two million dollars per year by selecting landfill gas from its Lena Road landfill as the primary fuel for the dryer. 5 tabs.

  9. Impact of intermittent aerations on leachate quality and greenhouse gas reduction in the aerobic-anaerobic landfill method.

    Science.gov (United States)

    Nag, Mitali; Shimaoka, Takayuki; Komiya, Teppei

    2016-09-01

    The aerobic-anaerobic landfill method (AALM) is a novel approach in solid waste management that could shorten the landfill post-closure period and minimize the environmental loads. In this study, the aerobic-anaerobic landfill method was evaluated by using intermittent aeration. In addition, the nitrification-denitrification process was assessed as a means of reducing the emission of greenhouse gases (GHGs) and improving the leachate quality during the degradation of the organic solid waste. The leachate quality and the gas composition in each of the reactors were measured during the experimental period (408days). The aeration process entailed the injection of air into plexiglass cylinders (200cm height×10 cm diameter), filled with fresh organic solid waste collected from a composting plant. Different aeration routines were applied, namely, continuous aeration (aerobic reactor A), aeration for three days/week (aerobic-anaerobic reactor B), aeration for 6h/day (aerobic-anaerobic reactor C), and no aeration (non-aerated reactor D). It was found that aerobic reactor A produced the best results in terms of reduction of GHGs and improvement of the leachate quality. The aerobic-anaerobic reactor C was found to be more effective than reactor B in respect of both the emission of GHGs and the leachate quality; moreover, compared with aerobic reactor A, energy costs were reduced by operating this reactor. The transition period phenomenon was investigated during an intensive seven-day experiment conducted on the discharged leachate obtained from aerobic-anaerobic reactors B and C. The experiment concerned the differences in the composition of the gas during the aeration and the non-aeration periods. It was found that the transition period between the aeration and non-aeration cycles, which followed the simultaneous nitrification-denitrification had a considerable effect on the leachate quality of both the reactors. The results indicated that AALM has the potential to reduce

  10. Seasonal greenhouse gas emissions (methane, carbon dioxide, nitrous oxide) from engineered landfills: daily, intermediate, and final California cover soils.

    Science.gov (United States)

    Bogner, Jean E; Spokas, Kurt A; Chanton, Jeffrey P

    2011-01-01

    Compared with natural ecosystems and managed agricultural systems, engineered landfills represent a highly managed soil system for which there has been no systematic quantification of emissions from coexisting daily, intermediate, and final cover materials. We quantified the seasonal variability of CH, CO, and NO emissions from fresh refuse (no cover) and daily, intermediate, and final cover materials at northern and southern California landfill sites with engineered gas extraction systems. Fresh refuse fluxes (g m d [± SD]) averaged CH 0.053 (± 0.03), CO 135 (± 117), and NO 0.063 (± 0.059). Average CH emissions across all cover types and wet/dry seasons ranged over more than four orders of magnitude (types, including both final covers, averaging 200 cm) cover materials, below which methanogenesis was well established, the variability in gaseous fluxes was attributable to cover thickness, texture, density, and seasonally variable soil moisture and temperature at suboptimal conditions for CH oxidation. Thin daily covers (30 cm local soil) and fresh refuse generally had the highest CO and NO fluxes, indicating rapid onset of aerobic and semi-aerobic processes in recently buried refuse, with rates similar to soil ecosystems and windrow composting of organic waste. This study has emphasized the need for more systematic field quantification of seasonal emissions from multiple types of engineered covers.

  11. CO2Explorer: Conducting Greenhouse-Gas Measurements of Landfills using a Small Fixed-wing UAV

    Science.gov (United States)

    Hollingsworth, Peter; Allen, Grant; Kabbabe, Khristopher; Pitt, Joseph

    2017-04-01

    Quantifying inventories of Greenhouse gas emissions, primarily Methane and Carbon Dioxide, from distributed sources such as a landfill has historically been undertaken using one of several ground based measurement techniques. These methods are either time and/or resource intensive. As a result regulatory agencies have started looking at the potential of using small-unmanned aircraft to supplement or supplant the current methods. The challenge of using a UAV to perform these tasks is the trade-off between accuracy, operational flexibility and operational productivity. This is driven by the state-of-the-art in measurement instruments, the operating environment at landfills and the regulatory/safety environment surrounding UAV operations. This work describes the development of the operational concept, and associated UAV measurement platform for the CO2Explorer. It looks at the scientific, engineering and possible policy trades and compares the use of small rotary and fixed-wing UAVs from both an operational and measurement perspective. This work also makes recommendations on system development and operation for users lacking in both systems engineering and operational experience.

  12. Landfill Gas Characterization and Leachate Removal at the Alachua County Southwest Landfill, Alachua County, Florida Through Utilization of a Mechanical Gas Collection System

    Science.gov (United States)

    1994-01-01

    0 0 2014 8 0 0 0 0 0 5 5 0 0 02016 3 0 0 0 0 0 2017 2 0 0 0 0 0 2018 1 0 0 0 0 0 * -- - .. 2 Ole>. 018 1 00 0 0 - - -- m- -- - - - m- -141 .-4 t...to the blowers from all three areas as configured now (without HIL) and as predicted by the Scholl Canyon model will be 400 cfa of methane or 404,800...1 2015 0 2016 0 2017 0 2018 0 CHAPTMR 6 CONCWSLIONS In 1991, a decision was made to install a gas collection system at the ACSVLf to prevent gas

  13. Landfill Gas Conversion to LNG and LCO{sub 2}. Phase II Final Report for January 25, 1999 - April 30, 2000

    Energy Technology Data Exchange (ETDEWEB)

    Brown, W. R.; Cook, W. J.; Siwajek, L. A.

    2000-10-20

    This report summarizes work on the development of a process to produce LNG (liquefied methane) for heavy vehicle use from landfill gas (LFG) using Acrion's CO{sub 2} wash process for contaminant removal and CO{sub 2} recovery.

  14. Mobile robots for localizing gas emission sources on landfill sites: is bio-inspiration the way to go?

    Science.gov (United States)

    Hernandez Bennetts, Victor; Lilienthal, Achim J; Neumann, Patrick P; Trincavelli, Marco

    2011-01-01

    Roboticists often take inspiration from animals for designing sensors, actuators, or algorithms that control the behavior of robots. Bio-inspiration is motivated with the uncanny ability of animals to solve complex tasks like recognizing and manipulating objects, walking on uneven terrains, or navigating to the source of an odor plume. In particular the task of tracking an odor plume up to its source has nearly exclusively been addressed using biologically inspired algorithms and robots have been developed, for example, to mimic the behavior of moths, dung beetles, or lobsters. In this paper we argue that biomimetic approaches to gas source localization are of limited use, primarily because animals differ fundamentally in their sensing and actuation capabilities from state-of-the-art gas-sensitive mobile robots. To support our claim, we compare actuation and chemical sensing available to mobile robots to the corresponding capabilities of moths. We further characterize airflow and chemosensor measurements obtained with three different robot platforms (two wheeled robots and one flying micro-drone) in four prototypical environments and show that the assumption of a constant and unidirectional airflow, which is the basis of many gas source localization approaches, is usually far from being valid. This analysis should help to identify how underlying principles, which govern the gas source tracking behavior of animals, can be usefully "translated" into gas source localization approaches that fully take into account the capabilities of mobile robots. We also describe the requirements for a reference application, monitoring of gas emissions at landfill sites with mobile robots, and discuss an engineered gas source localization approach based on statistics as an alternative to biologically inspired algorithms.

  15. Mobile Robots for Localizing Gas Emission Sources on Landfill Sites: Is Bio-Inspiration the Way to Go?

    Directory of Open Access Journals (Sweden)

    Victor eHernandez Bennetts

    2012-01-01

    Full Text Available Roboticists often take inspiration from animals for designing sensors, actuators or algorithms that control the behaviour of robots. Bio-inspiration is motivated with the uncanny ability of animals to solve complex tasks like recognizing and manipulating objects, walking on uneven terrains, or navigating to the source of an odour plume. In particular the task of tracking an odour plume up to its source has nearly exclusively been addressed using biologically inspired algorithms and robots have been developed, for example, to mimic the behaviour of moths, dungbeetles, or lobsters. In this paper we argue that biomimetic approaches to gas source localization are of limited use, primarily because animals differ fundamentally in their sensing and actuation capabilities from state-of-the-art gas-sensitive mobile robots. To support our claim, we compare actuation and chemical sensing available to mobile robots to the corresponding capabilities of moths. We further characterize airflow and chemosensor measurements obtained with three different robot platforms (two wheeled robots and one flying micro drone in four prototypical environments and show that the assumption of a constant and unidirectional airflow, which is at the basis of many gas source localization approaches, is usually far from being valid. This analysis should help to identify how underlying principles, which govern the gas source tracking behaviour of animals, can be usefully translated into gas source localization approaches that fully take into account the capabilities of mobile robots. We also describe the requirements for a reference application, monitoring of gas emissions at landfill sites with mobile robots, and discuss an engineered gas source localization approach based on statistics as an alternative to biologically-inspired algorithms.

  16. NEXT GENERATION GAS TURBINE SYSTEMS STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Benjamin C. Wiant; Ihor S. Diakunchak; Dennis A. Horazak; Harry T. Morehead

    2003-03-01

    Under sponsorship of the U.S. Department of Energy's National Energy Technology Laboratory, Siemens Westinghouse Power Corporation has conducted a study of Next Generation Gas Turbine Systems that embraces the goals of the DOE's High Efficiency Engines and Turbines and Vision 21 programs. The Siemens Westinghouse Next Generation Gas Turbine (NGGT) Systems program was a 24-month study looking at the feasibility of a NGGT for the emerging deregulated distributed generation market. Initial efforts focused on a modular gas turbine using an innovative blend of proven technologies from the Siemens Westinghouse W501 series of gas turbines and new enabling technologies to serve a wide variety of applications. The flexibility to serve both 50-Hz and 60-Hz applications, use a wide range of fuels and be configured for peaking, intermediate and base load duty cycles was the ultimate goal. As the study progressed the emphasis shifted from a flexible gas turbine system of a specific size to a broader gas turbine technology focus. This shift in direction allowed for greater placement of technology among both the existing fleet and new engine designs, regardless of size, and will ultimately provide for greater public benefit. This report describes the study efforts and provides the resultant conclusions and recommendations for future technology development in collaboration with the DOE.

  17. Evaluation of the Oedometer Tests of Municipal Landfill Waste Material

    Directory of Open Access Journals (Sweden)

    Imre Emőke

    2014-07-01

    Full Text Available The aim of the ongoing research is (i to develop a new biodegradation landfill technique so that the landfill gas production could be controlled and the utilisation of the landfill gas could economically be optimized, (ii to plan the energy utilisation of the landfill including individual and combined solutions (solar, wind, geothermal energy, energy storage using methanol etc.. [1, 2, 3

  18. A Flue Gas Tube for Thermoelectric Generator

    DEFF Research Database (Denmark)

    2013-01-01

    The invention relates to a flue gas tube (FGT) (1) for generation of thermoelectric power having thermoelectric elements (8) that are integrated in the tube. The FTG may be used in combined heat and power (CHP) system (13) to produce directly electricity from waste heat from, e.g. a biomass boiler...

  19. The use of RPAS in monitoring volume changes, subsidence and gas emissions from a landfill in Veneto Region, North east of Italy.

    Science.gov (United States)

    Busnardo, Enrico; Ravagnan, Riccardo; Castellarin, Nicola; Canella, Claudio; Gandolfo, Luca; Petrillo, Giovanni

    2017-04-01

    Public opinion consider landfills as a problematic waste disposal system. They are perceived as groundwater and air source of pollution, and unfortunately it is true. For this reason, Regional Environmental Agencies (ARPA) need data in order to figure out the potential pollution near landfills. Remotely Piloted Aircraft Systems (RPAS) with specific sensors, could be a better solution than traditional terrestrial sensors. They provide a better sampling at different altitudes. Therefore, a 3D diffusion gas model could be improved. This study case is about a solid urban waste landfill, located on the Venetian Po Plain in the south of the Veneto Region. The "electronic nose" on the RPAS, needs to be stand still at least 15 seconds while sampling. For this reason, in this study case a multicopter RPAS was used. The result was a 3D concentration map of pollutant gases. The map was related with meteorological data from a Regional meteorological station located near the landfill to identify the gas source. In the end, the study about the olfactory impact was made using the OdiGauss model, developed by the Agricultural and Environmental Sciences Department of Udine University. It was also compared with a simulation carried out with CALWin software.

  20. A review on utilization of combustible waste gas (II):Landfill gas,flare gas,associated gas and coalbed methane%可燃废气利用技术研究进展(Ⅱ):填埋气、火炬气、伴生天然气和煤矿瓦斯

    Institute of Scientific and Technical Information of China (English)

    王一坤; 陈国辉; 雷小苗; 王长安; 邓磊; 车得福

    2014-01-01

    The utilization of combustible waste gas is an important way of energy conservation and emission reduction.The progress in utilization technologies of landfill gas,flare gas,associated gas and coalbed methane has been presented.Due to the very low utilization ratio and insufficient resourceful utilization of landfill gas,the waste landfill treatment of which the leachate treatment and efficient LFG extraction and utilization are the key technologies should be widely popularized.Generally,the flare gas is fired to provide heat which is then recycled by waste heat boiler.Sometimes it can be directly burned in gas turbine for power generation.With low yield,the associated gas can be used as the inj ection fluid for oil production,or for field power generation.When the yield is high and stable,the associated gas can be transported by pipe-lines,liquid natural gas (LNG)and compressed natural gas (CNG)ships.The optimal utilization of low concentration coalbed methane is for gas-steam combined cycle power generation,of which the power gen-eration efficiency can reach up to higher than 45%.Usually,the coalbed methane is applied as assistant air in mine-mouth power plants,for the technical requirements and cost of this method are the lowest.%可燃废气利用是实现我国节能减排的重要途径之一。介绍了目前填埋气、火炬气、伴生天然气和煤矿瓦斯几种可燃废气的利用技术和工业应用现状。其中:填埋气的利用率很低,资源化利用技术不足,需大力推广以渗滤液处理、高效LFG抽排及利用为核心的填埋垃圾处理工艺;火炬气通常引入燃油或燃气锅炉加以利用,也可以将火炬气燃烧后利用余热锅炉回收热量,或者作为中等热值的气体,直接引入燃气轮机燃烧发电;伴生天然气的产量不高时,可以将其回注驱油或就地发电,产量高且稳定时,可以采用管道输送、液化天然气(LNG)和压缩天然气(CNG

  1. Estimating methane emissions from landfills based on rainfall, ambient temperature, and waste composition: The CLEEN model.

    Science.gov (United States)

    Karanjekar, Richa V; Bhatt, Arpita; Altouqui, Said; Jangikhatoonabad, Neda; Durai, Vennila; Sattler, Melanie L; Hossain, M D Sahadat; Chen, Victoria

    2015-12-01

    Accurately estimating landfill methane emissions is important for quantifying a landfill's greenhouse gas emissions and power generation potential. Current models, including LandGEM and IPCC, often greatly simplify treatment of factors like rainfall and ambient temperature, which can substantially impact gas production. The newly developed Capturing Landfill Emissions for Energy Needs (CLEEN) model aims to improve landfill methane generation estimates, but still require inputs that are fairly easy to obtain: waste composition, annual rainfall, and ambient temperature. To develop the model, methane generation was measured from 27 laboratory scale landfill reactors, with varying waste compositions (ranging from 0% to 100%); average rainfall rates of 2, 6, and 12 mm/day; and temperatures of 20, 30, and 37°C, according to a statistical experimental design. Refuse components considered were the major biodegradable wastes, food, paper, yard/wood, and textile, as well as inert inorganic waste. Based on the data collected, a multiple linear regression equation (R(2)=0.75) was developed to predict first-order methane generation rate constant values k as functions of waste composition, annual rainfall, and temperature. Because, laboratory methane generation rates exceed field rates, a second scale-up regression equation for k was developed using actual gas-recovery data from 11 landfills in high-income countries with conventional operation. The Capturing Landfill Emissions for Energy Needs (CLEEN) model was developed by incorporating both regression equations into the first-order decay based model for estimating methane generation rates from landfills. CLEEN model values were compared to actual field data from 6 US landfills, and to estimates from LandGEM and IPCC. For 4 of the 6 cases, CLEEN model estimates were the closest to actual.

  2. Development of a NASA standard gas generator

    Science.gov (United States)

    Bement, Laurence J.; Karp, Harold; Schimmel, Morry L.

    1993-01-01

    The goals of the NASA Standard Gas Generator (NSGG) Program are to create a NASA standard gas generating cartridge, characterize its performance, and make it readily available to users. A cartridge within the same envelope as the NASA Standard Initiator (NSI) has the greatest potential use. This potential use is described in viewgraph form. Our approach for NSGG development and qualification was planned to be conducted in several phases. Test methods were developed to evaluate output performance for a variety of potential applications. A feasibility study using modified NSI's was accomplished. Preliminary and final development will be conducted with a delta qualification to evaluate the effects of manufacturing lots and environments. Feasibility study results, feasibility study conclusions, and future plans are presented.

  3. Experimental and life cycle assessment analysis of gas emission from mechanically–biologically pretreated waste in a landfill with energy recovery

    Energy Technology Data Exchange (ETDEWEB)

    Di Maria, Francesco, E-mail: francesco.dimaria@unipg.it; Sordi, Alessio; Micale, Caterina

    2013-11-15

    Highlights: • Bio-methane landfill emissions from different period (0, 4, 8, 16 weeks) MTB waste have been evaluated. • Electrical energy recoverable from landfill gas ranges from 11 to about 90 kW h/tonne. • Correlation between oxygen uptake, energy recovery and anaerobic gas production shows R{sup 2} ranging from 0.78 to 0.98. • LCA demonstrate that global impact related to gaseous emissions achieve minimum for 4 week of MBT. - Abstract: The global gaseous emissions produced by landfilling the Mechanically Sorted Organic Fraction (MSOF) with different weeks of Mechanical Biological Treatment (MBT) was evaluated for an existing waste management system. One MBT facility and a landfill with internal combustion engines fuelled by the landfill gas for electrical energy production operate in the waste management system considered. An experimental apparatus was used to simulate 0, 4, 8 and 16 weeks of aerobic stabilization and the consequent biogas potential (Nl/kg) of a large sample of MSOF withdrawn from the full-scale MBT. Stabilization achieved by the waste was evaluated by dynamic oxygen uptake and fermentation tests. Good correlation coefficients (R{sup 2}), ranging from 0.7668 to 0.9772, were found between oxygen uptake, fermentation and anaerobic test values. On the basis of the results of several anaerobic tests, the methane production rate k (year{sup −1}) was evaluated. k ranged from 0.436 to 0.308 year{sup −1} and the bio-methane potential from 37 to 12 N m{sup 3}/tonne, respectively, for the MSOF with 0 and 16 weeks of treatment. Energy recovery from landfill gas ranged from about 11 to 90 kW h per tonne of disposed MSOF depending on the different scenario investigated. Life cycle analysis showed that the scenario with 0 weeks of pre-treatment has the highest weighted global impact even if opposite results were obtained with respect to the single impact criteria. MSOF pre-treatment periods longer than 4 weeks showed rather negligible variation

  4. A review of landfill microbiology research

    Energy Technology Data Exchange (ETDEWEB)

    Archer, D.; Reynolds, P.; Blakey, N.C.

    1995-05-01

    In May 1994 the DTI through ETSU commissioned WRc to undertake a comprehensive review of the landfill microbiology programme to date. The review has attempted to identify remaining gaps in knowledge which are most likely to find application in controlling the production of gas from landfills, and concludes with a list of recommendations for specific landfill process research which is likely to facilitate and optimise energy recovery from landfill. (UK)

  5. Bioreactor landfill

    Institute of Scientific and Technical Information of China (English)

    WANG Hao; XING Kai; Anthony Adzomani

    2004-01-01

    Following the population expansion, there is a growing threat brought by municipal solid waste (MSW) against environment and human health. Sanitary landfill is the most important method of MSW disposal in China. In contrast to the conventional landfill, this paper introduces a new technique named bioreactor landfill (BL). Mechanisms, operation conditions as well as the advantages and disadvantages of BL are also discussed in this paper.

  6. Turning a Liability into an Asset: Landfill Methane Recovery in India

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    Solid waste disposal sites are not often seen as opportunities for energy solutions. The waste that is disposed in open dumps and landfills generates methane and other gases as it decomposes, causing concerns about explosions, odours, and, increasingly, about the contribution of methane to global climate change. However, the liability of landfill gas (LFG) can be turned into an asset. Many countries regularly capture LFG as a strategy to improve landfill safety, generate electricity, reduce greenhouse gas emissions, and to earn carbon emission reduction credits (e.g. 40% for the United States, 25% for Australia). Many projects in developing countries are taking advantage of the United Nations Framework Convention on Climate Change (UNFCCC) Clean Development Mechanism (CDM) to earn carbon credits by capturing and combusting methane (e.g., the Sudokwon Landfill in Republic of South Korea, the Bandeirantes Landfill in Brazil and the Nanjing Tianjingwa Landfill in China). These Landfill Gas to Energy (LFGE) projects provide a valuable service to the environment and a potentially profitable business venture, providing benefits to local and regional communities.

  7. Gas Generation from Actinide Oxide Materials

    Energy Technology Data Exchange (ETDEWEB)

    George Bailey; Elizabeth Bluhm; John Lyman; Richard Mason; Mark Paffett; Gary Polansky; G. D. Roberson; Martin Sherman; Kirk Veirs; Laura Worl

    2000-12-01

    This document captures relevant work performed in support of stabilization, packaging, and long term storage of plutonium metals and oxides. It concentrates on the issue of gas generation with specific emphasis on gas pressure and composition. Even more specifically, it summarizes the basis for asserting that materials loaded into a 3013 container according to the requirements of the 3013 Standard (DOE-STD-3013-2000) cannot exceed the container design pressure within the time frames or environmental conditions of either storage or transportation. Presently, materials stabilized and packaged according to the 3013 Standard are to be transported in certified packages (the certification process for the 9975 and the SAFKEG has yet to be completed) that do not rely on the containment capabilities of the 3013 container. Even though no reliance is placed on that container, this document shows that it is highly likely that the containment function will be maintained not only in storage but also during transportation, including hypothetical accident conditions. Further, this document, by summarizing materials-related data on gas generation, can point those involved in preparing Safety Analysis Reports for Packages (SARPs) to additional information needed to assess the ability of the primary containment vessel to contain the contents and any reaction products that might reasonably be produced by the contents.

  8. Analysis of the economic potential of the landfill in the municipality of Chapeco - SC, Brazil; Analise do potencial economico do aterro sanitario do municipio de Chapeco - SC

    Energy Technology Data Exchange (ETDEWEB)

    Cansian, Maricy Moreno, Email: maricymc@gmail.com

    2006-07-01

    This study aims to evaluate the economic and environmental viability of the exploitation of methane gas (CH4) - biogas - concentrated at the bottom of the mountains of waste from landfill Chapeco for power generation. The landfill receives approximately of 80 tons / day, the vast majority of domestic origin.

  9. 21 CFR 866.2580 - Gas-generating device.

    Science.gov (United States)

    2010-04-01

    ...) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2580 Gas-generating device. (a) Identification. A gas-generating device is a device intended for medical purposes that...

  10. Assessment of soil-gas, soil, and water contamination at the former 19th Street landfill, Fort Gordon, Georgia, 2009-2010

    Science.gov (United States)

    Falls, W. Fred; Caldwell, Andral W.; Guimaraes, Wladmir B.; Ratliff, W. Hagan; Wellborn, John B.; Landmeyer, James E.

    2011-01-01

    Soil gas, soil, and water were assessed for organic and inorganic constituents at the former 19th Street landfill at Fort Gordon, Georgia, from February to September 2010. Passive soil-gas samplers were analyzed to evaluate organic constituents in the hyporheic zone and flood plain of a creek and soil gas within the estimated boundaries of the former landfill. Soil and water samples were analyzed to evaluate inorganic constituents in soil samples, and organic and inorganic constituents in the surface water of a creek adjacent to the landfill, respectively. This assessment was conducted to provide environmental constituent data to Fort Gordon pursuant to requirements of the Resource Conservation and Recovery Act Part B Hazardous Waste Permit process. The passive soil-gas samplers deployed in the water-saturated hyporheic zone and flood plain of the creek adjacent to the former landfill indicated the presence of total petroleum hydrocarbon (TPH) and octane above method detection levels in groundwater beneath the creek bed and flood plain at all 12 soil-gas sampler locations. The TPH concentrations ranged from 51.4 to 81.4 micrograms per liter. Octane concentrations ranged from 1.78 to 2.63 micrograms per liter. These detections do not clearly identify specific source areas in the former landfill; moreover, detections of TPH and octane in a soil-gas sampler installed at a seep on the western bank of the creek indicated the potential for these constituents to be derived from source areas outside the estimated boundaries of the former landfill. A passive soil-gas sampler survey was conducted in the former landfill from June 30 to July 5, 2010, and involved 56 soil-gas samplers that were analyzed for petroleum and halogenated compounds not classified as chemical agents or explosives. The TPH soil-gas mass exceeded 2.0 micrograms in 21 samplers. Most noticeable are the two sites with TPH detections which are located in and near the hyporheic zone and are likely to affect

  11. Closed landfills to solar energy power plants: Estimating the solar potential of closed landfills in California

    Science.gov (United States)

    Munsell, Devon R.

    Solar radiation is a promising source of renewable energy because it is abundant and the technologies to harvest it are quickly improving. An ongoing challenge is to find suitable and effective areas to implement solar energy technologies without causing ecological harm. In this regard, one type of land use that has been largely overlooked for siting solar technologies is closed or soon to be closed landfills. Utilizing Geographic Information System (GIS) based solar modeling; this study makes an inventory of solar generation potential for such sites in the state of California. The study takes account of various site characteristics in relation to the siting needs of photovoltaic (PV) geomembrane and dish-Stirling technologies (e.g., size, topography, closing date, solar insolation, presence of landfill gas recovery projects, and proximity to transmission grids and roads). This study reaches the three principal conclusions. First, with an estimated annual solar electricity generation potential of 3.7 million megawatt hours (MWh), closed or soon to be closed landfill sites could provide an amount of power significantly larger than California's current solar electric generation. Secondly, the possibility of combining PV geomembrane, dish-Stirling, and landfill gas (LFG) to energy technologies at particular sites deserves further investigation. Lastly, there are many assumptions, challenges, and limitations in conducting inventory studies of solar potential for specific sites, including the difficulty in finding accurate data regarding the location and attributes of potential landfills to be analyzed in the study. Furthermore, solar modeling necessarily simplifies a complex phenomenon, namely incoming solar radiation. Additionally, site visits, while necessary for finding details of the site, are largely impractical for a large scale study.

  12. 准好氧填埋工艺中通气管径对垃圾填埋气(LFG)影响研究及空气热力学计算%Impact of aeration conduit diameter on production of landfill gas in a semi- aerobic landfill

    Institute of Scientific and Technical Information of China (English)

    杜松; 金晶; 牟子申; 王迪; 赵瑞江; 崔宝山

    2011-01-01

    针对我国土地资源有限、垃圾产生量大的特点,准好氧填埋工艺逐渐成为中小型城市治理固体废物污染的首选技术.该工艺中,进入填埋堆体的空气量对垃圾填埋气(LFG)的产生及组分有重要的影响.为了确定准好氧填埋结构中竖直导气管与渗滤液导排主管直径的合理比例,在涿州市生活垃圾处理场建立了中试装置进行模拟准好氧填埋试验,并设置了直径分别为100、150、200ram的三种通气管(以下分别表示为DN100、DN150、DN200)与渗滤液导排管相连接,连续10周监测LFG中O2、CO2和CH4的体积分数,最后用热力学原理对数据进行数学计算和分析.结果表明,DN100填埋装置内,LFG中的O2无论是最终体积分数还是上升趋势都明显高于其他装置,在温室气体减排方面,CH4和CO2也得到了更为有效的抑制.通过理论计算可知,DN100、DN150和DN200的通气管排出气体量比为2:3:4,由于进气情况相同,因此,DN100的通气管向填埋堆体内部传输空气量最多.%Semi-aerobic landlfilling is becoming the main technology to solve the solid waste pollution problem in some medium and small cities in China because of land resource limitation and the large amount of garbage. In this technology, the amount of air which enters the landfill site has great impact on the generation and composition of landfill gas (LFG). We set up pilot plants to simulate semi-aerobic landfill technology at the Zhuozhou municipal solid waste landfill site. Three different diameters of aeration conduits, DN100, DN150 and DN200 ( 100mm, 150mm and 200mm ) were connected to the leachate drainage pipe. The concentration of gases in the LFG was monitored for 10 weeks continuously. The results show that the concentration and the tendency of O2 in LFG coming from the plant with the DN100 aeration conduit are much higher than that from the other two plants. The greenhouse gases CH4 and CO2 have been controlled more

  13. Livingston Parish Landfill Methane Recovery Project (Feasibility Study)

    Energy Technology Data Exchange (ETDEWEB)

    White, Steven

    2012-11-15

    The Woodside Landfill is owned by Livingston Parish, Louisiana and is operated under contract by Waste Management of Louisiana LLC. This public owner/private operator partnership is commonplace in the solid waste industry today. The landfill has been in operation since approximately 1988 and has a permitted capacity of approximately 41 million cubic yards. Based on an assumed in-place waste density of 0.94 ton per cubic yard, the landfill could have an expected design capacity of 39.3 million tons. The landfill does have an active landfill gas collection and control system (LFGCCS) in place because it meets the minimum thresholds for the New Source Performance Standards (NSPS). The initial LFGCS was installed prior to 2006 and subsequent phases were installed in 2007 and 2010. The Parish received a grant from the United States Department of Energy in 2009 to evaluate the potential for landfill gas recovery and utilization at the Woodside Landfill. This includes a technical and economic feasibility study of a project to install a landfill gas to energy (LFGTE) plant and to compare alternative technologies. The LFGTE plant can take the form of on-site electrical generation, a direct use/medium Btu option, or a high-Btu upgrade technology. The technical evaluation in Section 2 of this report concludes that landfill gas from the Woodside landfill is suitable for recovery and utilization. The financial evaluations in sections 3, 4, and 5 of this report provide financial estimates of the returns for various utilization technologies. The report concludes that the most economically viable project is the Electricity Generation option, subject to the Parish’s ability and willingness to allocate adequate cash for initial capital and/or to obtain debt financing. However, even this option does not present a solid return: by our estimates, there is a 19 year simple payback on the electricity generation option. All of the energy recovery options discussed in this report

  14. Waste Informatics: Establishing Characteristics of Contemporary U.S. Landfill Quantities and Practices.

    Science.gov (United States)

    Powell, Jon T; Pons, José C; Chertow, Marian

    2016-10-06

    Waste generation is expected to increase in most countries for many decades with landfill disposal still the dominant solid waste management method(1-3). Yet, operational characteristics of landfills are often poorly understood with comparative statistics substantially lacking. Here, we call for a more formal waste informatics to organize and standardize waste management knowledge at multiple spatial scales through analysis of recently reported data from 1232 U.S. landfills and other high resolution data sets. We create the first known estimate of available U.S. municipal waste stocks (8.5 billion tonnes) and go on to resolve these stocks at the county level, reflecting prospective urban mining opportunities. Our analysis of disposal rates and landfill capacities reveals that more than half of U.S. states have more than 25 years of life remaining. We also estimate the gross energy potential of landfill gas in the U.S. (338 billion MJ/yr) by examining 922 operational methane collection systems and demonstrate that the greatest energy recovery opportunities lie at landfills with existing collection systems and energy conversion infrastructure. Finally, we found that the number of landfills reaching the federally defined 30-year postclosure care period will more than triple in the coming two decades, with 264 sites expected by the year 2044, highlighting the need to develop and standardize metrics carefully to define and standardize when it is appropriate to end or scale back long-term landfill monitoring.

  15. Quantification of methane emissions from danish landfills

    DEFF Research Database (Denmark)

    Scheutz, Charlotte; Mønster, Jacob; Kjeldsen, Peter

    2013-01-01

    Whole-landfill methane emission was quantified using a tracer technique that combines controlled tracer gas release from the landfill with time-resolved concentration measurements downwind of the landfill using a mobile high-resolution analytical instrument. Methane emissions from 13 Danish...... landfills varied between 2.6 and 60.8 kg CH4 h–1. The highest methane emission was measured at the largest (in terms of disposed waste amounts) of the 13 landfills, whereas the lowest methane emissions (2.6-6.1 kgCH4 h–1) were measured at the older and smaller landfills. At two of the sites, which had gas...... collection, emission measurements showed that the gas collection systems only collected between 30-50% of the methane produced (assuming that the produced methane equalled the sum of the emitted methane and the collected methane). Significant methane emissions were observed from disposed shredder waste...

  16. Inverse Estimation of Temperature Profiles in Landfills Using Heat Recovery Fluids Measurements

    Directory of Open Access Journals (Sweden)

    C. Solisio

    2012-01-01

    Full Text Available In addition to leachate and gas emission analysis, temperature variations in municipal solid waste landfills are routinely monitored for safety and health reasons, such as the increased production of biogas or the danger of spontaneous combustion phenomena if the temperature exceeds 70–75°C. The increasing constraints on greenhouse gas emissions and the convenience of fuel and heat recovery have helped develop a global approach to landfills' operation and maintenance, generally referred to as bioreactor landfill management. The heat recovery piping we are presently designing can be a significant part of this approach. The heat gained by a fluid circulated in a closed network through the landfill is transferred to an external heat exchanger or used directly as warm water. Additionally, it can help reduce landfill temperature levels and control biogas generation. Since the pipes diameter is large enough to allow for a radial temperature gradient, this information can be used for an inverse estimation of the temperature profile in the landfill which constitutes the boundary conditions of the resulting heat transfer problem. In this paper, we describe an algorithm for regularising the resulting ill-posed free boundary estimation problem using sampled data of the heat recovery fluid on exiting the landfill.

  17. Performance evaluation of the bioreactor landfill in treatment and stabilisation of mechanically biologically treated municipal solid waste.

    Science.gov (United States)

    Lakshmikanthan, P; Sivakumar Babu, G L

    2017-03-01

    The potential of bioreactor landfills to treat mechanically biologically treated municipal solid waste is analysed in this study. Developing countries like India and China have begun to investigate bioreactor landfills for municipal solid waste management. This article describes the impacts of leachate recirculation on waste stabilisation, landfill gas generation, leachate characteristics and long-term waste settlement. A small-scale and large-scale anaerobic cell were filled with mechanically biologically treated municipal solid waste collected from a landfill site at the outskirts of Bangalore, India. Leachate collected from the same landfill site was recirculated at the rate of 2-5 times a month on a regular basis for 370 days. The total quantity of gas generated was around 416 L in the large-scale reactor and 21 L in the small-scale reactor, respectively. Differential settlements ranging from 20%-26% were observed at two different locations in the large reactor, whereas 30% of settlement was observed in the small reactor. The biological oxygen demand/chemical oxygen demand (COD) ratio indicated that the waste in the large reactor was stabilised at the end of 1 year. The performance of the bioreactor with respect to the reactor size, temperature, landfill gas and leachate quality was analysed and it was found that the bioreactor landfill is efficient in the treatment and stabilising of mechanically biologically treated municipal solid waste.

  18. Banshan Gas-Fired Turbine Generator Set Put into Operation

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ No.1 generator set of Banshan gas-fired power generation project, which is the first 9 FA heavy-duty gas turbine generator set in China that has drawn much attention, was successfully put into operation and merged into power grid at 21:30 in June 2, three months ahead of schedule.

  19. Assessment of methane generation, oxidation, and emission in a subtropical landfill test cell.

    Science.gov (United States)

    Moreira, João M L; Candiani, Giovano

    2016-08-01

    This paper presents results of a methane balance assessment in a test cell built in a region with a subtropical climate near São Paulo, Brazil. Measurements and calculations were carried out to obtain the total methane emission to the atmosphere, the methane oxidation rate in the cover, and the total methane generation rate in the test cell. The oxidation rate was obtained through a calculation scheme based on a vertical one-dimensional methane transport in the cover region. The measured maximum and mean methane fluxes to the atmosphere were 124.4 and 15.87 g m(-2) d(-1), respectively. The total methane generation rate obtained for the test cell was 0.0380 ± 0.0075 mol s(-1). The results yielded that 69 % of the emitted methane occurred through the central well and 31 % through the cover interface with the atmosphere. The evaluations of the methane oxidation fraction for localized conditions in the lateral embankment of the test cell yielded 0.36 ± 0.11, while for the whole test cell yielded 0.15 ± 0.10. These results conciliate localized and overall evaluations reported in the literature. The specific methane generation rate obtained for the municipal solid waste with an age of 410 days was 317 ± 62 mol year(-1) ton(-1). This result from the subtropical São Paulo region is lower than reported figures for tropical climates and higher than reported figures for temperate climates.

  20. Quantifying capital goods for waste landfilling

    DEFF Research Database (Denmark)

    Brogaard, Line Kai-Sørensen; Stentsøe, Steen; Willumsen, Hans Christian

    2013-01-01

    Materials and energy used for construction of a hill-type landfill of 4 million m3 were quantified in detail. The landfill is engineered with a liner and leachate collections system, as well as a gas collection and control system. Gravel and clay were the most common materials used, amounting...... to approximately 260 kg per tonne of waste landfilled. The environmental burdens from the extraction and manufacturing of the materials used in the landfill, as well as from the construction of the landfill, were modelled as potential environmental impacts. For example, the potential impact on global warming was 2.......5 kg carbon dioxide (CO2) equivalents or 0.32 milli person equivalents per tonne of waste. The potential impacts from the use of materials and construction of the landfill are low-to-insignificant compared with data reported in the literature on impact potentials of landfills in operation...

  1. Quantification of landfill methane using modified Intergovernmental Panel on Climate Change's waste model and error function analysis.

    Science.gov (United States)

    Govindan, Siva Shangari; Agamuthu, P

    2014-10-01

    Waste management can be regarded as a cross-cutting environmental 'mega-issue'. Sound waste management practices support the provision of basic needs for general health, such as clean air, clean water and safe supply of food. In addition, climate change mitigation efforts can be achieved through reduction of greenhouse gas emissions from waste management operations, such as landfills. Landfills generate landfill gas, especially methane, as a result of anaerobic degradation of the degradable components of municipal solid waste. Evaluating the mode of generation and collection of landfill gas has posted a challenge over time. Scientifically, landfill gas generation rates are presently estimated using numerical models. In this study the Intergovernmental Panel on Climate Change's Waste Model is used to estimate the methane generated from a Malaysian sanitary landfill. Key parameters of the model, which are the decay rate and degradable organic carbon, are analysed in two different approaches; the bulk waste approach and waste composition approach. The model is later validated using error function analysis and optimum decay rate, and degradable organic carbon for both approaches were also obtained. The best fitting values for the bulk waste approach are a decay rate of 0.08 y(-1) and degradable organic carbon value of 0.12; and for the waste composition approach the decay rate was found to be 0.09 y(-1) and degradable organic carbon value of 0.08. From this validation exercise, the estimated error was reduced by 81% and 69% for the bulk waste and waste composition approach, respectively. In conclusion, this type of modelling could constitute a sensible starting point for landfills to introduce careful planning for efficient gas recovery in individual landfills.

  2. Utilization of biogas from sanitary landfill for generation of electrical energy in Sao Paulo: a case study; Aproveitamento do biogas proveniente de aterro sanitario para geracao de energia eletrica em Sao Paulo: estudo de caso

    Energy Technology Data Exchange (ETDEWEB)

    Garcilasso, Vanessa Pecora; Coelho, Suani Teixeira Coelho [Centro Nacional de Referencia em Biomassa (CENBIO), Sao Paulo, SP (Brazil); Velazquez, Silvia Maria Stortini Gonzalez [Universitaria Presbiteriana Mackenzie, Sao Paulo, SP (Brazil)

    2010-07-01

    Utilization of the biogas proceeding from urban solid residues for electricity generation: case study in Sao Paulo. The biogas, generated from organic matter degradation, is composed by a mixture of gases, the main components being carbon dioxide and methane, which is a greenhouse effect gas with global warming potential around 21 times greater when compared to CO{sub 2}. Biogas production is possible from a great variety of organic residues such as urban solid residues, residues from agricultural and livestock activities, swine livestock, sewage mud, among others. The sanitary landfills may count on techniques of capture of the produced biogas and its later burning in flare, where the methane is transformed in CO{sub 2}, minimizing the environmental impact. Besides the opportunity of reducing the environmental damages, biogas can also be used as fuel for generating electricity, thus adding environmental gain and reduction of costs, due to the diminishing of purchase of the energy consumed in the concessionaire. In this context, this article presents the project of utilization of biogas proceeding from urban solid residues for electricity generation and gas illumination, developed by CENBIO. This project is currently in development and the obtained results will provide technical and economic subsidies for its replication. (author)

  3. Incorporating in-cylinder pressure data to predict NO{sub x} emissions from spark-ignition engines fueled with landfill gas/hydrogen mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Kornbluth, Kurt; McCaffrey, Zach; Erickson, Paul A. [Department of Mechanical and Aerospace Engineering, University of California, One Shields Avenue, Davis, CA 95616 (United States)

    2009-11-15

    A 0.745 L 2-cylinder spark-ignition engine was operated with compressed natural gas and with simulated landfill gas (60% CH{sub 4} and 40% CO{sub 2} by volume) containing hydrogen concentrations of 0, 30%, 40%, and 50% (by volume of the CH{sub 4} in the fuel) at constant rpm. This empirical data was compared with predictions from three existing semi-empirical engine models, using a first-law-based finite heat release model to correlate measured in-cylinder pressure data and burn rate for each fuel mixture. Of the three models only a two zone model incorporating thermal and prompt NO{sub x} came within 25% of predicting the measured NO{sub x} emissions. (author)

  4. Estimating water content in an active landfill with the aid of GPR.

    Science.gov (United States)

    Yochim, April; Zytner, Richard G; McBean, Edward A; Endres, Anthony L

    2013-10-01

    Landfill gas (LFG) receives a great deal of attention due to both negative and positive environmental impacts, global warming and a green energy source, respectively. However, predicting the quantity of LFG generated at a given landfill, whether active or closed is difficult due to the heterogeneities present in waste, and the lack of accurate in situ waste parameters like water content. Accordingly, ground penetrating radar (GPR) was evaluated as a tool for estimating in situ water content. Due to the large degree of subsurface heterogeneity and the electrically conductive clay cap covering landfills, both of which affect the transmission of the electromagnetic pulses, there is much scepticism concerning the use of GPR to quantify in situ water content within a municipal landfill. Two landfills were studied. The first landfill was used to develop the measurement protocols, while the second landfill provided a means of confirming these protocols. GPR measurements were initially completed using the surface GPR approach, but the lack of success led to the use of borehole (BH) GPR. Both zero offset profiling (ZOP) and multiple offset gathers (MOG) modes were tried, with the results indicating that BH GPR using the ZOP mode is the most simple and efficient method to measure in situ water content. The best results were obtained at a separation distance of 2m, where higher the water content, smaller the effective separation distance. However, an increase in water content did appear to increase the accuracy of the GPR measurements. For the effective separation distance of 2m at both landfills, the difference between GPR and lab measured water contents were reasonable at 33.9% for the drier landfill and 18.1% for the wetter landfill. Infiltration experiments also showed the potential to measure small increases in water content.

  5. Heat Recovery From Tail Gas Incineration To Generate Power

    Energy Technology Data Exchange (ETDEWEB)

    Tawfik, Tarek

    2010-09-15

    Many industrial processes result in tail gas wastes that must be flared or incinerated to abide with environmental guidelines. Tail gas incineration occurs in several chemical processes resulting in high-temperature exhaust gas that simply go to the stack, thus wasting all that valuable heat! This paper discusses useful heat recovery and electric power generation utilizing available heat in exhaust gas from tail gas incinerators. This heat will be recovered in a waste-heat recovery boiler that will produce superheated steam to expand in a steam turbine to generate power. A detailed cost estimate is presented.

  6. Did state renewable portfolio standards induce technical change in methane mitigation in the U.S. landfill sector?

    Science.gov (United States)

    Delhotal, Katherine Casey

    Landfill gas (LFG) projects use the gas created from decomposing waste, which is approximately 49% methane, and substitute it for natural gas in engines, boilers, turbines, and other technologies to produce energy or heat. The projects are beneficial in terms of increased safety at the landfill, production of a cost-effective source of energy or heat, reduced odor, reduced air pollution emissions, and reduced greenhouse gas emissions. However, landfills sometimes face conflicting policy incentives. The theory of technical change shows that the diffusion of a technology or groups of technologies increases slowly in the beginning and then picks up speed as knowledge and better understanding of using the technology diffuses among potential users. Using duration analysis, data on energy prices, State and Federal policies related to landfill gas, renewable energy, and air pollution, as well as control data on landfill characteristics, I estimate the influence and direction of influence of renewable portfolio standards (RPS). The analysis found that RPS positively influences the diffusion of landfill gas technologies, encouraging landfills to consider electricity generation projects over direct sales of LFG to another facility. Energy price increases or increased revenues for a project are also critical. Barriers to diffusion include air emission permits in non-attainment areas and policies, such as net metering, which promote other renewables over LFG projects. Using the estimates from the diffusion equations, I analyze the potential influence of a Federal RPS as well as the potential interaction with a Federal, market based climate change policy, which will increase the revenue of a project through higher energy sale prices. My analysis shows that a market based climate change policy such as a cap-and-trade or carbon tax scheme would increase the number of landfill gas projects significantly more than a Federal RPS.

  7. NEXT GENERATION GAS TURBINE (NGGT) SYSTEMS STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Unknown

    2001-12-05

    to how they could serve multiple applications, both in terms of incorporation of technology into current products, as well as to an NGGT product. In summary, potential program costs are shown for development of the candidate systems along with the importance of future DOE enabling participation. Three main conclusions have been established via this study: (1) Rapid recent changes within the power generation regulatory environment and the resulting ''bubble'' of gas turbine orders has altered the timing and relative significance associated with the conclusions of the ADL study upon which the original DOE NGGT solicitation was based. (2) Assuming that the relevant technologies were developed and available for an NGGT market opportunity circa 2010, the top candidate system that meets or exceeds the DOE PRDA requirements was determined to be a hybrid aero-derivative/heavy duty concept. (3) An investment by DOE of approximately $23MM/year to develop NGGT technologies near/mid term for validation and migration into a reasonable fraction of the installed base of GE F-class products could be leveraged into $1.2B Public Benefit, with greatest benefits resulting from RAM improvements. In addition to the monetary Public Benefit, there is also significant benefit in terms of reduced energy consumption, and reduced power plant land usage.

  8. Characterization of thermal properties of municipal solid waste landfills.

    Science.gov (United States)

    Faitli, József; Magyar, Tamás; Erdélyi, Attila; Murányi, Attila

    2015-02-01

    Municipal waste landfills represent not only a source of landfill gases, but a source of thermal energy as well. The heat in landfills is generated by physical, chemical and microbiological processes. The goal of our study was to characterize the thermal properties of municipal solid waste (MSW) samples of the given landfill. A new apparatus was designed and constructed to measure heat flow. A systematic test series of 17 discrete measurements was carried out with municipal waste samples of 1.0-1.7 m(3). The thermal conductivity, heat diffusivity and specific heat capacity of the samples were determined. Analysing the results of the sampling and our experiments it was realized that the theoretical fundaments should be clarified. Two theories were developed for the serial and for the parallel heat flow in three phase disperse systems. The serial and parallel models resulted in different theoretical estimations. The measured thermal conductivity and heat diffusivity were better characterized by the parallel heat flow estimations. The results show that heat can flow parallel in solid, liquid and gas phases. Characterization of thermal properties serves to establish the fundament of heat extraction from municipal waste landfills.

  9. Contribution of individual waste fractions to the environmental impacts from landfilling of municipal solid waste

    DEFF Research Database (Denmark)

    Manfredi, Simone; Tonini, Davide; Christensen, Thomas Højlund

    2010-01-01

    PE/tonne). These savings are mostly determined by the waste fractions characterized by a high content of biogenic carbon (paper, organics, other combustible waste). These savings are due to emissions from energy generation avoided by landfill gas utilization, and by the storage of biogenic carbon in the landfill due......A number of LCA-based studies have reported on the environmental performance of landfilling of mixed waste, but little is known about the relative contributions of individual waste fractions to the overall impact potentials estimated for the mixed waste. In this paper, an empirical model has been...... used to estimate the emissions to the environment from landfilling of individual waste fractions. By means of the LCA-model EASEWASTE, the emissions estimated have been used to quantify how much of the overall impact potential for each impact category is to be attributed to the individual waste...

  10. Environmental assessment of low-organic waste landfill scenarios by means of life-cycle assessment modelling (EASEWASTE).

    Science.gov (United States)

    Manfredi, Simone; Christensen, Thomas H; Scharff, Heijo; Jacobs, Joeri

    2010-02-01

    The environmental performance of two low-organic waste landfill scenarios ('low-organic-energy' and 'low-organic-flare') was developed and compared with two household waste landfill scenarios ('household-energy' and 'household-flare') by means of LCA-modelling. The LCA-modelling was made for 1 tonne of wet waste landfilled and the environmental aspects were evaluated for a 100-year period after disposal. The data utilized in the LCA-calculations to model the first 10-20 years of landfilling of the two low-organic waste scenarios make extensive use of site-specific data from the Nauerna Landfill (The Netherlands), but average data from other comparable, existing landfills were used too. As data from full-scale landfills do not cover more than 30-40 years of landfilling, data from laboratory simulations and accelerated tests of limited scale were also utilized. The life-cycle impact assessments show that the low-organic waste scenarios achieved better environmental performance than the household waste scenarios with regard to both ordinary and toxicity-related environmental impact categories. This indicates that the reduction of organic matter accepted at landfills (as prescribed by the European Union Landfill Directive: Council Directive 1999/31/EC, EU, Brussels, 1999) can be a successful approach to decrease the environmental loads in several impact categories in comparison with landfilling of waste with significant organic content. However, when utilization of landfill gas is accounted for in the life-cycle impact assessment calculation, the small gas generation in low-organic waste landfills reduced the actual potential for energy generation and therefore the environmental savings obtained were reduced proportionally. Groundwater pollution from input of leachate was also evaluated and the WHO (Guidelines for Drinking-water Quality; WHO, Geneva, 2006) guideline for drinking water quality was assumed as reference. The results show that low-organic waste landfills

  11. Differences in volatile methyl siloxane (VMS) profiles in biogas from landfills and anaerobic digesters and energetics of VMS transformations

    Energy Technology Data Exchange (ETDEWEB)

    Tansel, Berrin, E-mail: tanselb@fiu.edu; Surita, Sharon C.

    2014-11-15

    Highlights: • In the digester gas, D4 and D5 comprised the 62% and 27% if siloxanes, respectively. • In landfill gas, the bulk of siloxanes were TMSOH (58%) followed by D4 (17%). • Methane utilization may be a possible mechanism for TMSOH formation in the landfills. • The geometric configurations of D4 and D5 molecules make them very stable. - Abstract: The objectives of this study were to compare the types and levels of volatile methyl siloxanes (VMS) present in biogas generated in the anaerobic digesters and landfills, evaluate the energetics of siloxane transformations under anaerobic conditions, compare the conditions in anaerobic digesters and municipal solid waste (MSW) landfills which result in differences in siloxane compositions. Biogas samples were collected at the South District Wastewater Treatment Plant and South Dade Landfill in Miami, Florida. In the digester gas, D4 and D5 comprised the bulk of total siloxanes (62% and 27%, respectively) whereas in the landfill gas, the bulk of siloxanes were trimethylsilanol (TMSOH) (58%) followed by D4 (17%). Presence of high levels of TMSOH in the landfill gas indicates that methane utilization may be a possible reaction mechanism for TMSOH formation. The free energy change for transformation of D5 and D4 to TMSOH either by hydrogen or methane utilization are thermodynamically favorable. Either hydrogen or methane should be present at relatively high concentrations for TMSOH formation which explains the high levels present in the landfill gas. The high bond energy and bond distance of the Si–O bond, in view of the atomic sizes of Si and O atoms, indicate that Si atoms can provide a barrier, making it difficult to break the Si–O bonds especially for molecules with specific geometric configurations such as D4 and D5 where oxygen atoms are positioned inside the frame formed by the large Si atoms which are surrounded by the methyl groups.

  12. Fluxes of methane between landfills and the atmosphere: Natural and engineered controls

    Energy Technology Data Exchange (ETDEWEB)

    Bogner, J. [Argonne National Lab., IL (United States); Meadows, M. [ETSU, Harwell, Oxfordshire (United Kingdom); Czepiel, P. [Harvard Univ., Cambridge, MA (United States)

    1997-08-01

    Field measurement of landfill methane emissions indicates natural variability spanning more than 2 seven orders of magnitude, from approximately 0.0004 to more than 4000 g m{sub -2} day{sup -1}. This wide range reflects net emissions resulting from production (methanogenesis), consumption (methanotrophic oxidation), and gaseous transport processes. The determination of an {open_quotes}average{close_quotes} emission rate for a given field site requires sampling designs and statistical techniques which consider spatial and temporal variability. Moreover, particularly at sites with pumped gas recovery systems, it is possible for methanotrophic microorganisms in aerated cover soils to oxidize all of the methane from landfill sources below and, additionally, to oxidize methane diffusing into cover soils from atmospheric sources above. In such cases, a reversed soil gas concentration gradient is observed in shallow cover soils, indicating bidirectional diffusional transport to the depth of optimum methane oxidation. Rates of landfill methane oxidation from field and laboratory incubation studies range up to 166 g m{sup -2} day{sup -1} among the highest for any natural setting, providing an effective natural control on net emissions. Estimates of worldwide landfill methane emissions to the atmosphere have ranged from 9 to 70 Tg yr{sup -1}, differing mainly in assumed methane yields from estimated quantities of landfilled refuse. At highly controlled landfill sites in developed countries, landfill methane is often collected via vertical wells or horizontal collectors. Recovery of landfill methane through engineered systems can provide both environmental and energy benefits by mitigating subsurface migration, reducing surface emissions, and providing an alternative energy resource for industrial boiler use, on-site electrical generation, or upgrading to a substitute natural gas.

  13. The Application Of Biofilter System For Reduction Of Methane Emissions From Modern Sanitary Landfills

    Science.gov (United States)

    Sung, K.; Park, S.

    2007-12-01

    Increased atmospheric concentrations of greenhouse gases (GHG) caused by anthropogenic activities has been related to global climate change. Methane, the second most important GHG after CO2, is 21 times more effective at trapping heat than CO2. Therefore, methane emission control is of utmost importance for global warming reduction. To minimize leachate production and protect groundwater resources, modern sanitary landfills are equipped with composite covers and gas collection systems. Methane from modern sanitary landfills is vented directly to the atmosphere, except for some of the largest landfills where it is recovered as energy and burned at the site. However, the efficiency of energy recovery systems in larger landfills is reduced as the amount of CH4 generated from landfill begins to decrease. In this study, the performance of a lab-scale model biofilter system was investigated to treat CH4 gas emitted from modern sanitary landfills by conducting batch and column experiments using landfill cover soil amended with earthworm cast as the filter bed medium. From the batch experiments to measure the influence of moisture content and temperature of the filter medium on CH4 removal capacity of a biofilter system, the optimum moisture content and temperature were found to be 10-15% by weight and 25-35°C, respectively. The column experiment was conducted to measure the influence of inlet CH4 concentration and CH4 loading rate on CH4 removal capacity of a biofilter system. As the inlet CH4 concentration decreased, the percentage of CH4 oxidized increased. Up to a CH4 loading rate of 2785 g CH4 m3 h- 1 (EBRT = 7.7 min), the CH4 removal efficiency of the biofilter was able to reach 100%. Based on the results of the study, the installation of a properly managed biofilter system should be capable of achieving a reduction in atmospheric CH4 emissions from modern sanitary landfills at low CH4 generation stage.

  14. Demonstration and Verification of a Turbine Power Generation System Utilizing Renewable Fuel: Landfill Gas

    Science.gov (United States)

    2013-09-01

    weight of the equipment and concrete pads. The heaviest integrated components (turbine, oxidizer, piping and supporting steel work) weigh about 25...DataTaker™ data logger and retrieved via cellular router on a weekly basis. Raw data were retrieved each week and appended into the ‘raw data’ tab of...Poster presentation 2010 ESTCP Symposium Poster presentation 2011 ESTCP Symposium Poster and presentation in renewable energy panel 2011 Exhibition

  15. Demonstration and Verification of a Turbine Power Generation System Utilizing Renewable Fuel: Landfill Gas

    Science.gov (United States)

    2013-09-01

    The FP250 integrates a modified conventional micro-turbine ( Ingersoll Rand MT250, now manufactured by FlexEnergy Energy Systems) of proven design...conventional micro-turbine ( Ingersoll Rand MT250, now manufactured by Flex Energy Systems) of proven design with a proprietary gradual thermal oxidizer in

  16. Landfill gas generation and emission at Danish waste disposal sites receiving low-organic waste

    DEFF Research Database (Denmark)

    Mou, Zishen

    De modtagne affaldstyper på moderne danske affaldsdeponeringsanlæg har de senere år ændret karakter hen i mod affaldstyper med et lavt indhold af organisk stof. Gennemførte undersøgelser har imidlertidig vist at der stadig produceres deponigas på affaldsdeponeringsanlæggene, dog oftest ikke i så ...

  17. Landfill gas generation and emission at Danish waste disposal sites receiving low-organic waste

    DEFF Research Database (Denmark)

    Mou, Zishen

    De modtagne affaldstyper på moderne danske affaldsdeponeringsanlæg har de senere år ændret karakter hen i mod affaldstyper med et lavt indhold af organisk stof. Gennemførte undersøgelser har imidlertidig vist at der stadig produceres deponigas på affaldsdeponeringsanlæggene, dog oftest ikke i så ...

  18. Gas-fired Power Generation in India: Challenges and opportunities

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    India's fast growing economy needs to add 100,000 MW power generating capacity between 2002-2012. Given limitations to the use of coal in terms of environmental considerations, quality and supply constraints, gas is expected to play an increasingly important role in India's power sector. This report briefs NMC Delegates on the potential for gas-fired power generation in India and describes the challenges India faces to translate the potential for gas-fired power generation into reality.

  19. Gas-fired Power Generation in India: Challenges and opportunities

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    India's fast growing economy needs to add 100,000 MW power generating capacity between 2002-2012. Given limitations to the use of coal in terms of environmental considerations, quality and supply constraints, gas is expected to play an increasingly important role in India's power sector. This report briefs NMC Delegates on the potential for gas-fired power generation in India and describes the challenges India faces to translate the potential for gas-fired power generation into reality.

  20. Geochemical and VOC-constraints on landfill gas age and attenuation characteristics: A case study from a waste disposal facility in Southern California.

    Science.gov (United States)

    Hagedorn, Benjamin; Kerfoot, Henry B; Verwiel, Mark; Matlock, Bruce

    2016-07-01

    In this study, a multi-tracer approach was applied to a complex, methane-impacted site in Southern California to (1) distinguish between natural gas and landfill gas (LFG)-derived methane impacts at site perimeter gas probes, (2) estimate the relative age of the LFG at these probes, and (3) document natural attenuation trends during a 3-year monitoring period. Relationships between methane and ethane values suggest that at the majority of probes, methane is from LFG and not from natural gas and that the relative contribution of LFG methane at these probes has increased over the monitoring period. To evaluate whether LFG is attenuating in the subsurface, the relative age of LFG was estimated by comparing readily degraded VOCs that are major constituents in LFG (toluene in this case) with those resistant to degradation (Freons). Time-series data trends are consistent with several probes being impacted by fresh LFG from recent releases that occurred after the update of the local LFG collection and control system (LFGCCS). Data further indicate some probes to be only affected by legacy LFG from a past release that occurred prior to the LFGCCS update and that, because of a lack of oxygen in the subsurface, had not been fully degraded. The outlined attenuation evaluation methodology is potentially applicable to other sites or even groundwater contaminants; however, the assessment is limited by the degree of homogeneity of the LFG source composition and non-LFG-derived toluene inputs to the analyzed samples.

  1. Lifecycle greenhouse gas emissions of coal, conventional and unconventional natural gas for electricity generation

    Science.gov (United States)

    An analysis of the lifecycle greenhouse gas (GHG) emissions associated with natural gas use recently published by Howarth et al. (2011) stated that use of natural gas produced from shale formations via hydraulic fracturing would generate greater lifecycle GHG emissions than petro...

  2. Gas generation from transuranic waste degradation: data summary and interpretation

    Energy Technology Data Exchange (ETDEWEB)

    Molecke, M.A.

    1979-12-01

    A comprehensive review of all applicable gas generation data resulting from the degradation of existing and potential forms of transuranic-contaminated wastes is presented. Extensive experimental studies have been performed under both realistic environmental conditions expected in the Waste Isolation Pilot Plant and overtest conditions. Degradation mechanisms investigated were radiolysis, thermal decomposition and dewatering, bacterial action, and chemical corrosion. Waste matrices studied include cellulosics, plastics, rubbers, organic composite, concrete-TRU ash, asphalt, process sludges, and mild steel. Measured gas generation rates are presented in terms of gas moles/year/drum of waste and in G(gas) values for radiolysis. The effects of multiple variables on gas generation are also described. 7 figures, 15 tables.

  3. Advanced On Board Inert Gas Generation System (OBBIGS) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Valcor Engineering Corporation proposes to develop an advanced On Board Inert Gas Generation System, OBIGGS, for aircraft fuel tank inerting to prevent hazardous...

  4. Gas Generation from K East Basin Sludges - Series II Testing

    Energy Technology Data Exchange (ETDEWEB)

    Bryan, Samuel A.; Delegard, Calvin H.; Schmidt, Andrew J.; Sell, Rachel L.; Silvers, Kurt L.; Gano, Susan R.; Thornton, Brenda M.

    2001-03-14

    This report describes work to examine the gas generation behavior of actual K East (KE) Basin floor, pit and canister sludge. Mixed and unmixed and fractionated KE canister sludge were tested, along with floor and pit sludges from areas in the KE Basin not previously sampled. The first report in this series focused on gas generation from KE floor and canister sludge collected using a consolidated sampling technique. The third report will present results of gas generation testing of irradiated uranium fuel fragments with and without sludge addition. The path forward for management of the K Basin Sludge is to retrieve, ship, and store the sludge at T Plant until final processing at some future date. Gas generation will impact the designs and costs of systems associated with retrieval, transportation and storage of sludge.

  5. Generation of Local Concentration Gradients by Gas-Liquid Contacting

    NARCIS (Netherlands)

    de Jong, J.; Verheijden, Pascal W.; Lammertink, Rob G.H.; Wessling, Matthias

    2008-01-01

    We present a generic concept to create local concentration gradients, based on the absorption of gases or vapors in a liquid. A multilayer microfluidic device with crossing gas and liquid channels is fabricated by micromilling and used to generate multiple gas-liquid contacting regions, separated by

  6. Applications for Solid Propellant Cool Gas Generator Technology

    Science.gov (United States)

    van der List, M.; van Vliet, L. D.; Sanders, H. M.; Put, P. A. G.; Elst, J. W. E. C.

    2004-10-01

    In 2002 and 2003, Bradford Engineering B.V. conducted, in corporation with the Dutch research institute TNO Prins Maurits Laboratory (PML) a SME study for ESA-ESTEC for the identification of spaceflight applications and on-ground demonstration of Solid Propellant Cool Gas Generator (SPCGG) technology. This innovative technology has been developed by TNO-PML while Bradford Engineering also brought in its experience in spaceflight hardware development and manufacturing. The Solid Propellant Cool Gas Generator (SPCGG) technology allows for pure gas generation at ambient temperatures, as opposed to conventional solid propellant gas generators. This makes the SPCGG technology interesting for a wide range of terrestrial spaceflight applications. During the first part of the study, a variety of potential applications have been identified and three applications were selected for a more detailed quantitative study. In the third phase a ground demonstration was performed successfully for a cold gas propulsion system application. During the actual demonstration test, 10 cool gas generators were mounted and all operated successfully in sequence, demonstrating good repeatability of the produced amount of gas and pressure.

  7. NEW APPROACH TO ADDRESSING GAS GENERATION IN RADIOACTIVE MATERIAL PACKAGING

    Energy Technology Data Exchange (ETDEWEB)

    Watkins, R; Leduc, D; Askew, N

    2009-06-25

    Safety Analysis Reports for Packaging (SARP) document why the transportation of radioactive material is safe in Type A(F) and Type B shipping containers. The content evaluation of certain actinide materials require that the gas generation characteristics be addressed. Most packages used to transport actinides impose extremely restrictive limits on moisture content and oxide stabilization to control or prevent flammable gas generation. These requirements prevent some users from using a shipping container even though the material to be shipped is fully compliant with the remaining content envelope including isotopic distribution. To avoid these restrictions, gas generation issues have to be addressed on a case by case basis rather than a one size fits all approach. In addition, SARP applicants and review groups may not have the knowledge and experience with actinide chemistry and other factors affecting gas generation, which facility experts in actinide material processing have obtained in the last sixty years. This paper will address a proposal to create a Gas Generation Evaluation Committee to evaluate gas generation issues associated with Safety Analysis Reports for Packaging material contents. The committee charter could include reviews of both SARP approved contents and new contents not previously evaluated in a SARP.

  8. Evaluating the biochemical methane potential (BMP) of low-organic waste at Danish landfills

    DEFF Research Database (Denmark)

    Mou, Zishen; Scheutz, Charlotte; Kjeldsen, Peter

    2014-01-01

    The biochemical methane potential (BMP) is an essential parameter when using first order decay (FOD) landfill gas (LFG) generation models to estimate methane (CH4) generation from landfills. Different categories of waste (mixed, shredder and sludge waste) with a low-organic content and temporarily...... stored combustible waste were sampled from four Danish landfills. The waste was characterized in terms of physical characteristics (TS, VS, TC and TOC) and the BMP was analyzed in batch tests. The experiment was set up in triplicate, including blank and control tests. Waste samples were incubated at 55 C...... for more than 60 days, with continuous monitoring of the cumulative CH4 generation. Results showed that samples of mixed waste and shredder waste had similar BMP results, which was in the range of 5.4–9.1 kg CH4/ton waste (wet weight) on average. As a calculated consequence, their degradable organic carbon...

  9. A microfluidic chip for generating reactive plasma at gas-gas interface formed in laminar flow

    Science.gov (United States)

    Hashimoto, Masahiro; Tsukasaki, Katsuki; Kumagai, Shinya; Sasaki, Minoru

    2015-01-01

    A gas-gas interface is used for generating a localized reactive plasma flow at an atmospheric pressure. A microfluidic chip is fabricated as the reactor integrating a small plasma source located upstream. Within a Y-shaped microchannel, a discharging gas flows with a chemical gas. Owing to the small width of the microchannel, the gas flow is stabilized in a laminar flow. The resultant gas-gas interface is formed in the area where two gases flow facing each other activating the chemical gas through the energetic species in the discharging gas. A characteristic stream pattern is observed as the etching profile of a carbon film with a sub-µm sharp step change that can be explained by the spatial distribution of the reactive oxygen. This etching profile is different from that obtained when plasma discharging occurs near the channel exit being affected by the turbulent flow.

  10. Landfills, Landfills, Published in 2003, Taylor County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Landfills dataset, was produced all or in part from Published Reports/Deeds information as of 2003. It is described as 'Landfills'. Data by this publisher are...

  11. Neural Network Modeling and Prediction of Methane Fraction in Biogas from Landfill Bioreactors

    Directory of Open Access Journals (Sweden)

    A Ghavidel

    2009-09-01

    Full Text Available "n "nBackgrounds and Objectives:A number of different technologies have recently been studied todetermine the best use of biogas, however, to choose optimize technologies of using biogas for energy recovery it is necessary to monitor and predict the methane percentage of biogas. In this study, a method is proposed for predicting the methane fraction in landfill gas originating from Labscalelandfill bioreactors, based on neural network."nMaterials and Methods: In this study, two different systems were applied, to predict the methane fraction in landfill gas as a final product of anaerobic digestion, we used the leachate specifications as input parameters. In system I (C1, the leachate generated from a fresh-waste reactor was drained to recirculation tank, and recycled. In System II (C2, the leachate generated from a fresh waste landfill reactor was fed through a well-decomposed refuse landfill reactor, and at the same time, the leachate generated from a well-decomposed refuse landfill reactor recycled to a fresh waste landfill reactor."nResults: There is very good agreement in the trends between forecasted and measured data. R valuesare 0.999 and 0.997, and the obtained Root mean square error values are 1.098 and 2.387 for training and test data, respectively"nConclusion: The proposed method can significantly predict the methane fraction in landfill gasoriginating and, consequently, neural network can be use to optimize the dimensions of a plant using biogas for energy (i.e. heat and/or electricity recovery and monitoring system.

  12. Gas Generation of Heated PBX 9502

    Energy Technology Data Exchange (ETDEWEB)

    Holmes, Matthew David [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Parker, Gary Robert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-10-07

    Uniaxially pressed samples of PBX 9502 were heated until self-ignition (cookoff) in order to collect pressure and temperature data relevant for model development. Samples were sealed inside a small gas-tight vessel, but were mechanically unconfined. Long-duration static pressure rise, as well as dynamic pressure rise during the cookoff event, were recorded. Time-lapse photography of the sample was used to measure the thermal expansion of the sample as a function of time and temperature. High-speed videography qualitatively characterized the mechanical behavior and failure mechanisms at the time of cookoff. These results provide valuable input to modeling efforts, in order to improve the ability to predict pressure output during cookoff as well as the effect of pressure on time-toignition.

  13. Comparison of first-order-decay modeled and actual field measured municipal solid waste landfill methane data.

    Science.gov (United States)

    Amini, Hamid R; Reinhart, Debra R; Niskanen, Antti

    2013-12-01

    The first-order decay (FOD) model is widely used to estimate landfill gas generation for emissions inventories, life cycle assessments, and regulation. The FOD model has inherent uncertainty due to underlying uncertainty in model parameters and a lack of opportunities to validate it with complete field-scale landfill data sets. The objectives of this paper were to estimate methane generation, fugitive methane emissions, and aggregated collection efficiency for landfills through a mass balance approach using the FOD model for gas generation coupled with literature values for cover-specific collection efficiency and methane oxidation. This study is unique and valuable because actual field data were used in comparison with modeled data. The magnitude and variation of emissions were estimated for three landfills using site-specific model parameters and gas collection data, and compared to vertical radial plume mapping emissions measurements. For the three landfills, the modeling approach slightly under-predicted measured emissions and over-estimated aggregated collection efficiency, but the two approaches yielded statistically equivalent uncertainties expressed as coefficients of variation. Sources of uncertainty include challenges in large-scale field measurement of emissions and spatial and temporal fluctuations in methane flow balance components (generated, collected, oxidized, and emitted methane). Additional publication of sets of field-scale measurement data and methane flow balance components will reduce the uncertainty in future estimates of fugitive emissions.

  14. Landfill reduction experience in The Netherlands

    Energy Technology Data Exchange (ETDEWEB)

    Scharff, Heijo, E-mail: h.scharff@afvalzorg.nl

    2014-11-15

    Highlights: • ‘Zero waste’ initiatives never consider risks, side effects or experience of achieved low levels of landfill. • This paper provides insight into what works and what not. • Where strong gradients in regulations and tax occur between countries, waste will find its way to landfills across borders. • Strong landfill reduction can create a fierce competition over the remaining waste to be landfilled resulting in losses. • At some point a public organisation should take responsibility for the operation of a ‘safety net’ in waste management. - Abstract: Modern waste legislation aims at resource efficiency and landfill reduction. This paper analyses more than 20 years of landfill reduction in the Netherlands. The combination of landfill regulations, landfill tax and landfill bans resulted in the desired landfill reduction, but also had negative effects. A fierce competition developed over the remaining waste to be landfilled. In 2013 the Dutch landfill industry generated €40 million of annual revenue, had €58 million annual costs and therefore incurred an annual loss of €18 million. It is not an attractive option to prematurely end business. There is a risk that Dutch landfill operators will not be able to fulfil the financial obligations for closure and aftercare. Contrary to the polluter pays principle the burden may end up with society. EU regulations prohibiting export of waste for disposal are in place. Strong differentials in landfill tax rate between nations have nevertheless resulted in transboundary shipment of waste and in non-compliance with the self-sufficiency and proximity principles. During the transformation from a disposal society to a recycling society, it is important to carefully plan required capacity and to guide the reorganisation of the landfill sector. At some point, it is no longer profitable to provide landfill services. It may be necessary for public organisations or the state to take responsibility for the

  15. Chemical looping reforming of generator gas

    Energy Technology Data Exchange (ETDEWEB)

    Mendiara, T.; Jensen, Anker; Glarborg, P.

    2010-02-15

    The main objective of this work is to investigate the carbon deposition during reforming of hydrocarbons in a Chemical Looping Reformer (CLR). This knowledge is needed to asses the viability of the CLR technology in reforming tar from biomass gasification preserving lighter hydrocarbons and minimizing the carbon formation during the process. Two different setups were used to test the reactivity of the different samples in the conditions of interest for the tar reforming process: 1) Fixed bed flow reactor (FR), and 2) Thermogravimetric analyzer (TGA). In the experiments, the gas atmosphere was switched from reducing to oxidizing atmosphere in every cycle. During the oxidizing cycle, the carrier was regenerated using a mixture of oxygen and nitrogen. Four different oxygen carriers based on nickel (Ni40 and Ni60), manganese (Mn) and ilmenite (Fe) were tested. In the tests, toluene was used to simulate the tars. The Fe and the Mn carrier reacted to a small extent with methane at the highest temperature studied, 800 degrees C. The Ni-carriers did not react at 600 degrees C at first, but they showed some reactivity after having been activated at the higher temperature. Carbon formation occurred with the Ni-carriers, more so with the Ni60 than the Ni40. Ni40, Mn and Fe were activated at the higher temperature. However, Fe showed only low capacity. Ni60 showed no capability of tar reforming. Ni40 showed a high tendency to carbon formation at 800 degrees C, but the formation could be lowered by changing some parameters. Mn formed almost no carbon. Ni40 and Mn were chosen for further studies. Carbon deposition occurred for both Ni40 and Mn, but the amount deposited for Ni40 was about 10 times bigger. Ni40 reacted with the methane and toluene only at 800 degrees C. The conversion over Mn was not as big as for toluene alone. Carbon was formed from carbon monoxide on the Ni40 carrier and on the Mn, but to a much less extent on the latter one. The presence of hydrogen decreased

  16. Determination of nonylphenol isomers in landfill leachate and municipal wastewater using steam distillation extraction coupled with comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry

    Science.gov (United States)

    Zhang, Caixiang; Eganhouse, Robert P.; Pontolillo, James; Cozzarelli, Isabelle M.; Wang, Yanxin

    2012-01-01

    4-Nonylphenols (4-NPs) are known endocrine disruptors and by-products of the microbial degradation of nonylphenol polyethoxylate surfactants. One of the challenges to understanding the toxic effects of nonylphenols is the large number of isomers that may exist in environmental samples. In order to attribute toxic effects to specific compounds, a method is needed for the separation and quantitation of individual nonylphenol isomers. The pre-concentration methods of solvent sublimation, solid-phase extraction or liquid–liquid extraction prior to chromatographic analysis can be problematic because of co-extraction of thousands of compounds typically found in complex matrices such as municipal wastewater or landfill leachate. In the present study, steam distillation extraction (SDE) was found to be an effective pre-concentration method for extraction of 4-NPs from leachate and wastewater, and comprehensive two-dimensional gas chromatography (GC × GC) coupled with fast mass spectral data acquisition by time-of-flight mass spectrometry (ToFMS) enhanced the resolution and identification of 4-NP isomers. Concentrations of eight 4-NP isomers were determined in leachate from landfill cells of different age and wastewater influent and effluent samples. 4-NP isomers were about 3 times more abundant in leachate from the younger cell than the older one, whereas concentrations in wastewater effluent were either below detection limits or <1% of influent concentrations. 4-NP isomer distribution patterns were found to have been altered following release to the environment. This is believed to reflect isomer-specific degradation and accumulation of 4-NPs in the aquatic environment.

  17. Generator gas as a fuel to power a diesel engine

    Directory of Open Access Journals (Sweden)

    Tutak Wojciech

    2014-01-01

    Full Text Available The results of gasification process of dried sewage sludge and use of generator gas as a fuel for dual fuel turbocharged compression ignition engine are presented. The results of gasifying showed that during gasification of sewage sludge is possible to obtain generator gas of a calorific value in the range of 2.15  2.59 MJ/m3. It turned out that the generator gas can be effectively used as a fuel to the compression ignition engine. Because of gas composition, it was possible to run engine with partload conditions. In dual fuel operation the high value of indicated efficiency was achieved equal to 35%, so better than the efficiency of 30% attainable when being fed with 100% liquid fuel. The dual fuel engine version developed within the project can be recommended to be used in practice in a dried sewage sludge gasification plant as a dual fuel engine driving the electric generator loaded with the active electric power limited to 40 kW (which accounts for approx. 50% of its rated power, because it is at this power that the optimal conditions of operation of an engine dual fuel powered by liquid fuel and generator gas are achieved. An additional advantage is the utilization of waste generated in the wastewater treatment plant.

  18. Gas generation in incinerator ash; Gasbildning i aska

    Energy Technology Data Exchange (ETDEWEB)

    Arm, Maria; Lindeberg, Johanna; Rodin, Aasa; Oehrstroem, Anna; Backman, Rainer; Oehman, Marcus; Bostroem, Dan

    2006-02-15

    In recent years, explosions have occurred in certain phases of ash handling in Sweden. Investigations have revealed that hydrogen may have been present in all cases. The hydrogen is believed to be generated by chemical reactions of aluminium and other metals within the ash in the presence of water. The purpose with this study is to increase the knowledge of gas generation of incinerator ash. Thereby, guides for appropriate ash management can be introduced and the risk for further explosions prevented. The study has comprised analyses of the ash properties, such as chemical and physical composition and the pH, of ash from 14 incineration plants (mostly waste incineration plants). Different fractions of ash materials representing different parts of the process in each plant have been analysed. Furthermore, the fuel and the technical differences between the plants have been analysed. A tool for measuring the gas generation in the laboratory has been developed and the gas generation of the different ash materials at natural and increased pH was measured. Gas analyses and thermodynamic calculations have also been performed. The results showed that: bottom ash from fluidised bed boilers generated small amounts of gas at increased pH, much smaller amounts than the idle pass, cyclone and filter ash did, bottom ash from grate fired boilers generated more gas at increased pH than their cyclone ash and filter ash, with exception of the Linkoeping plant, all bio waste incineration plants generated ash with low gas generation potential, all fly ash materials with a gas generation potential of more than 10 l/kg originated from municipal waste incineration plants, filter ash that had been stored in oxygen rich environment generated significant less gas than fresh filter ash of the same origin, hardly any other gases were generated apart from hydrogen (very small amounts of acetone, furane, benzene and most likely methane were detected in some of the ash materials), there were no

  19. From waste disposal service to power supplier. A landfill is turned into a futuristic energy farm; Vom Entsorger zum Versorger. Eine Muellkippe wird zum futuristischen Energiepark

    Energy Technology Data Exchange (ETDEWEB)

    Boeckh, Martin

    2011-11-15

    On a landfill operated by the waste disposal utility of the Rhein-Neckar district, an energy farm is currently under construction. Apart from a PV system and landfill gas production, a biomass-fuelled heating power station was recently commissioned. Further plants will follow, i.e. pellets production, power generation by a Wankel engine, and a futuristic plant for pressureless oil production from waste plastics.

  20. Environmental assessment of solid waste landfilling technologies by means of LCA-modeling.

    Science.gov (United States)

    Manfredi, Simone; Christensen, Thomas H

    2009-01-01

    By using life cycle assessment (LCA) modeling, this paper compares the environmental performance of six landfilling technologies (open dump, conventional landfill with flares, conventional landfill with energy recovery, standard bioreactor landfill, flushing bioreactor landfill and semi-aerobic landfill) and assesses the influence of the active operations practiced on these performances. The environmental assessments have been performed by means of the LCA-based tool EASEWASTE, whereby the functional unit utilized for the LCA is "landfilling of 1ton of wet household waste in a 10m deep landfill for 100 years". The assessment criteria include standard categories (global warming, nutrient enrichment, ozone depletion, photo-chemical ozone formation and acidification), toxicity-related categories (human toxicity and ecotoxicity) and impact on spoiled groundwater resources. Results demonstrate that it is crucially important to ensure the highest collection efficiency of landfill gas and leachate since a poor capture compromises the overall environmental performance. Once gas and leachate are collected and treated, the potential impacts in the standard environmental categories and on spoiled groundwater resources significantly decrease, although at the same time specific emissions from gas treatment lead to increased impact potentials in the toxicity-related categories. Gas utilization for energy recovery leads to saved emissions and avoided impact potentials in several environmental categories. Measures should be taken to prevent leachate infiltration to groundwater and it is essential to collect and treat the generated leachate. The bioreactor technologies recirculate the collected leachate to enhance the waste degradation process. This allows the gas collection period to be reduced from 40 to 15 years, although it does not lead to noticeable environmental benefits when considering a 100 years LCA-perspective. In order to more comprehensively understand the influence

  1. Reactive intermediates in the gas phase generation and monitoring

    CERN Document Server

    Setser, D W

    2013-01-01

    Reactive Intermediates in the Gas Phase: Generation and Monitoring covers methods for reactive intermediates in the gas phase. The book discusses the generation and measurement of atom and radical concentrations in flow systems; the high temperature flow tubes, generation and measurement of refractory species; and the electronically excited long-lived states of atoms and diatomic molecules in flow systems. The text also describes the production and detection of reactive species with lasers in static systems; the production of small positive ions in a mass spectrometer; and the discharge-excite

  2. Reduction of greenhouse gases emissions listed in the Kyoto Protocol by the utilization of landfill gas using solid oxide fuel cells; Reducao das emissoes de gases de efeito estufa listados no protocolo de Quioto pelo aproveitamento do gas gerado em aterros sanitarios utilizando celulas a combustivel de oxido solido. Estudo de caso do aterro municipal de Santo Andre, SP, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Paris, Alexandre Gellert

    2007-07-01

    In the last few years, the Kyoto Protocol had been a subject very debated, at first, in a restricted niche, manly academics and professionals related to the area of climate changes. On 16th February 2005 the Kyoto Protocol entered into force and with this a lot of publicity all over the world, so today is common to hear about it at the mass communications media. The extension of the subject is broad, this work discuss the utilization of one the Kyoto's flexibility mechanisms, to contribute to financing the use of the landfill gas in the solid oxide fuel cells. Among the three mechanisms presented in the Kyoto Protocol, the clean development mechanism (CDM) in article 12, is the only one that can be implemented by non-Annex I countries, the case of Brazil. In other hand, the issue of solid waste in Brazil is critical. Even being illegal, most of the solid waste goes to uncontrolled areas in open air places 'lixoes', causing degradation of the environment and the communities around this areas, and also emission of green house gases (GHG), deregulating the global climate system. Decontaminate this areas and the construction of landfills to replace than, considering the landfill as a bioreactor, and the utilization of the biogas to generate power can improve nowadays picture that we are facing. The utilization of an innovative alternative technology as the solid oxide fuel cell (SOFC) instead the conventional technologies will be more efficient and environmentally better. Among other barriers the cost is pointed as the biggest. In this context, the SOFC is the most expensive fuel cell, so the utilization of CDM can contribute to finance the application of this technology. Scenarios were made of 250 kW, 500 kW, 1,000 kW, 5,000 kW and 10,000 kW of installed power using biogas from the Municipal Landfill of Santo Andre. The calculations of the emission factor were done ex ante and ex post according to ACM0002. Comparing the costs of the installed power

  3. Mitigation of methane emission from an old unlined landfill in Klintholm, Denmark using a passive biocover system

    Energy Technology Data Exchange (ETDEWEB)

    Scheutz, Charlotte; Pedersen, Rasmus Broe [Department of Environmental Engineering, Technical University of Denmark, DK-2800 Kgs. Lyngby (Denmark); Petersen, Per Haugsted [Ramboll Denmark A/S, DK-5100 Odense C (Denmark); Jørgensen, Jørgen Henrik Bjerre [Klintholm I/S, DK-5874 Hasselager (Denmark); Ucendo, Inmaculada Maria Buendia; Mønster, Jacob G. [Department of Environmental Engineering, Technical University of Denmark, DK-2800 Kgs. Lyngby (Denmark); Samuelsson, Jerker [FluxSense AB/Chalmers University of Technology, SE-412 96 Göteborg (Sweden); Kjeldsen, Peter, E-mail: pekj@env.dtu.dk [Department of Environmental Engineering, Technical University of Denmark, DK-2800 Kgs. Lyngby (Denmark)

    2014-07-15

    Highlights: • An innovative biocover system was constructed on a landfill cell to mitigate the methane emission. • The biocover system had a mitigation efficiently of typically 80%. • The system also worked efficiently at ambient temperatures below freezing. • A whole landfill emission measurement tool was required to document the biocover system efficiency. - Abstract: Methane generated at landfills contributes to global warming and can be mitigated by biocover systems relying on microbial methane oxidation. As part of a closure plan for an old unlined landfill without any gas management measures, an innovative biocover system was established. The system was designed based on a conceptual model of the gas emission patterns established through an initial baseline study. The study included construction of gas collection trenches along the slopes of the landfill where the majority of the methane emissions occurred. Local compost materials were tested as to their usefulness as bioactive methane oxidizing material and a suitable compost mixture was selected. Whole site methane emission quantifications based on combined tracer release and downwind measurements in combination with several local experimental activities (gas composition within biocover layers, flux chamber based emission measurements and logging of compost temperatures) proved that the biocover system had an average mitigation efficiency of approximately 80%. The study showed that the system also had a high efficiency during winter periods with temperatures below freezing. An economic analysis indicated that the mitigation costs of the biocover system were competitive to other existing greenhouse gas mitigation options.

  4. LANDFILL GAS CONVERSION TO LNG AND LCO{sub 2}. PHASE 1, FINAL REPORT FOR THE PERIOD MARCH 1998-FEBRUARY 1999

    Energy Technology Data Exchange (ETDEWEB)

    COOK,W.J.; NEYMAN,M.; SIWAJEK,L.A.; BROWN,W.R.; VAN HAUWAERT,P.M.; CURREN,E.D.

    1998-02-25

    Process designs and economics were developed to produce LNG and liquid carbon dioxide (CO{sub 2}) from landfill gas (LFG) using the Acrion CO{sub 2} wash process. The patented Acrion CO{sub 2} wash process uses liquid CO{sub 2} to absorb contaminants from the LFG. The process steps are compression, drying, CO{sub 2} wash contaminant removal and CO{sub 2} recovery, residual CO{sub 2} removal and methane liquefaction. Three flowsheets were developed using different residual CO{sub 2} removal schemes. These included physical solvent absorption (methanol), membranes and molecular sieves. The capital and operating costs of the flowsheets were very similar. The LNG production cost was around ten cents per gallon. In parallel with process flowsheet development, the business aspects of an eventual commercial project have been explored. The process was found to have significant potential commercial application. The business plan effort investigated the economics of LNG transportation, fueling, vehicle conversion, and markets. The commercial value of liquid CO{sub 2} was also investigated. This Phase 1 work, March 1998 through February 1999, was funded under Brookhaven National laboratory contract 725089 under the research program entitled ``Liquefied Natural Gas as a Heavy Vehicle Fuel.'' The Phase 2 effort will develop flowsheets for the following: (1) CO{sub 2} and pipeline gas production, with the pipeline methane being liquefied at a peak shaving site, (2) sewage digester gas as an alternate feedstock to LFG and (3) the use of mixed refrigerants for process cooling. Phase 2 will also study the modification of Acrion's process demonstration unit for the production of LNG and a market site for LNG production.

  5. Controlled landfill project, Yolo County, California

    Energy Technology Data Exchange (ETDEWEB)

    Augenstein, D.C.; Benemann, J.R. [Inst. for Environmental Management Inc., Palo Alto, CA (United States); Yazdani, R.; Kieffer, J.; Akau, H. [Yolo County Dept. of Public Works, Woodland, CA (United States)

    2004-07-01

    Controlled bioreactor landfill tests were conducted at the Central Landfill in Yolo County, California to determine how to maximize methane recovery for energy use while minimizing methane emissions to the atmosphere. Landfill gas has the potential to contribute 1 per cent to the total electricity supplies in the United States. The failure to use methane to its potential is due to unpredictability, variability and slow rates of production and low recovery factors of landfill methane. The main challenge lies in accelerating the biological decomposition and treatment of the municipal solid waste (MSW). The breakdown rate of MWS can be increased through the use of basic landfill biochemical engineering methods. This study demonstrated the influence of adding supplemental water and leachate to the MSW. Moisture, temperature and gas pressures were recorded throughout the waste mass. This study also focused on eliminating volatile organic compounds, reducing the costs for post-closure landfill care, improving the economics of scale for energy use, improving leachate quality and reducing the costs for off-site disposal of landfill leachate. It was shown that methane capture was maximized when a surface membrane was placed over a permeable layer and when the bioreactor was operated at a slight vacuum. Accelerated methane production and waste reduction were noted in the enhanced test cell. The first order rate constant for methanogenesis was about 0.45 per year. The control cell stopped producing gas after one year. 12 refs., 4 figs.

  6. GEOTECHNICAL DESIGN OF SOLID WASTE LANDFILL SITES

    Directory of Open Access Journals (Sweden)

    Suat AKBULUT

    2003-02-01

    Full Text Available Solid waste landfills are important engineering structures for protection of wastes, decrease of environmental pollution, and especially prevention of soil and water pollution. Solid wastes should conveniently be maintained in landfill areas to control environmental pollution caused by waste disposals. Until the middle of this century clay liners were used for maintenance of waste disposal, but it was observed that these liner systems were insufficient. Today thinner and less permeable liner systems are constructed by using synthetic materials. In this study, by evaluating the waste landfills, site assessment of landfills and construction of natural and synthetic liner systems were summarized respectively, and especially the design properties of these systems were examined intensively. Also, leachate collection and removal facilities, landfill gas collection unites, and final cover unites were evaluated in a detailed way.

  7. Biomass & Natural Gas Based Hydrogen Fuel For Gas Turbine (Power Generation)

    Science.gov (United States)

    Significant progress has been made by major power generation equipment manufacturers in the development of market applications for hydrogen fuel use in gas turbines in recent years. Development of a new application using gas turbines for significant reduction of power plant CO2 e...

  8. Noble Gas Clusters and Nanoplasmas in High Harmonic Generation

    CERN Document Server

    Aladi, M; Rácz, P; Földes, I B

    2015-01-01

    We report a study of high harmonic generation from noble gas clusters of xenon atoms in a gas jet. Harmonic spectra were investigated as a function of backing pressure, showing spectral shifts due to the nanoplasma electrons in the clusters. At certain value of laser intensity this process may oppose the effect of the well-known ionization-induced blueshift. In addition, these cluster-induced harmonic redshifts may give the possibility to estimate cluster density and cluster size in the laser-gas jet interaction range.

  9. Mitigation of methane emissions in a pilot-scale biocover system at the AV Miljø Landfill, Denmark: 2. Methane oxidation

    DEFF Research Database (Denmark)

    Scheutz, Charlotte; Cassini, Filippo; De Schoenmaeker, Jan

    2017-01-01

    Greenhouse gas mitigation at landfills by methane (CH4) oxidation in engineered biocover systems is believed to be a cost effective technology but so far a full quantitative evaluation of the efficiency of the technology in full scale has only been carried out in a few cases. A third generation...... semi-passive biocover system was constructed at the AV Miljø Landfill, Denmark. The biocover was fed by landfill gas pumped out of three leachate collection wells. An innovative gas distribution system was used to overcome the often observed uneven gas distribution to the active CH4 oxidation layer...... methods; the carbon mass balance method (based on CH4 and carbon dioxide (CO2) concentrations in the deeper part of the cover and CH4 and CO2 surface flux measurements) and a new-developed tracer gas mass balance method (based on CH4 and tracer inlet fluxes and CH4 and tracer surface flux measurements...

  10. Harmonization of initial estimates of shale gas life cycle greenhouse gas emissions for electric power generation.

    Science.gov (United States)

    Heath, Garvin A; O'Donoughue, Patrick; Arent, Douglas J; Bazilian, Morgan

    2014-08-05

    Recent technological advances in the recovery of unconventional natural gas, particularly shale gas, have served to dramatically increase domestic production and reserve estimates for the United States and internationally. This trend has led to lowered prices and increased scrutiny on production practices. Questions have been raised as to how greenhouse gas (GHG) emissions from the life cycle of shale gas production and use compares with that of conventionally produced natural gas or other fuel sources such as coal. Recent literature has come to different conclusions on this point, largely due to differing assumptions, comparison baselines, and system boundaries. Through a meta-analytical procedure we call harmonization, we develop robust, analytically consistent, and updated comparisons of estimates of life cycle GHG emissions for electricity produced from shale gas, conventionally produced natural gas, and coal. On a per-unit electrical output basis, harmonization reveals that median estimates of GHG emissions from shale gas-generated electricity are similar to those for conventional natural gas, with both approximately half that of the central tendency of coal. Sensitivity analysis on the harmonized estimates indicates that assumptions regarding liquids unloading and estimated ultimate recovery (EUR) of wells have the greatest influence on life cycle GHG emissions, whereby shale gas life cycle GHG emissions could approach the range of best-performing coal-fired generation under certain scenarios. Despite clarification of published estimates through harmonization, these initial assessments should be confirmed through methane emissions measurements at components and in the atmosphere and through better characterization of EUR and practices.

  11. Quantifying capital goods for waste landfilling.

    Science.gov (United States)

    Brogaard, Line K; Stentsøe, Steen; Willumsen, Hans Christian; Christensen, Thomas H

    2013-06-01

    Materials and energy used for construction of a hill-type landfill of 4 million m(3) were quantified in detail. The landfill is engineered with a liner and leachate collections system, as well as a gas collection and control system. Gravel and clay were the most common materials used, amounting to approximately 260 kg per tonne of waste landfilled. The environmental burdens from the extraction and manufacturing of the materials used in the landfill, as well as from the construction of the landfill, were modelled as potential environmental impacts. For example, the potential impact on global warming was 2.5 kg carbon dioxide (CO2) equivalents or 0.32 milli person equivalents per tonne of waste. The potential impacts from the use of materials and construction of the landfill are low-to-insignificant compared with data reported in the literature on impact potentials of landfills in operation. The construction of the landfill is only a significant contributor to the impact of resource depletion owing to the high use of gravel and steel.

  12. T2LBM Version 1.0: Landfill bioreactor model for TOUGH2

    Energy Technology Data Exchange (ETDEWEB)

    Oldenburg, Curtis M.

    2001-05-22

    The need to control gas and leachate production and minimize refuse volume in landfills has motivated the development of landfill simulation models that can be used by operators to predict and design optimal treatment processes. T2LBM is a module for the TOUGH2 simulator that implements a Landfill Bioreactor Model to provide simulation capability for the processes of aerobic or anaerobic biodegradation of municipal solid waste and the associated flow and transport of gas and liquid through the refuse mass. T2LBM incorporates a Monod kinetic rate law for the biodegradation of acetic acid in the aqueous phase by either aerobic or anaerobic microbes as controlled by the local oxygen concentration. Acetic acid is considered a proxy for all biodegradable substrates in the refuse. Aerobic and anaerobic microbes are assumed to be immobile and not limited by nutrients in their growth. Methane and carbon dioxide generation due to biodegradation with corresponding thermal effects are modeled. The numerous parameters needed to specify biodegradation are input by the user in the SELEC block of the TOUGH2 input file. Test problems show that good matches to laboratory experiments of biodegradation can be obtained. A landfill test problem demonstrates the capabilities of T2LBM for a hypothetical two-dimensional landfill scenario with permeability heterogeneity and compaction.

  13. Efficient and Safe Chemical Gas Generators with Nanocomposite Reactive Materials

    Science.gov (United States)

    2015-11-30

    ammonia borane has been developed that involves the reaction of mechanically alloyed Al·Mg powder with water as a source of heat for ammonia borane...Edward L. Dreizin, Evgeny Shafirovich. Hydrogen generation from ammonia borane and water through combustion reactions with mechanically alloyed... Synthesis , 21 - 24 October 2013, South Padre Island, TX, p. 211. Rodriguez, D., Machado, M., Shafirovich, E., and Dreizin, E.L., “Gas Generating

  14. Landfill is an important atmospheric mercury emission source

    Institute of Scientific and Technical Information of China (English)

    FENG Xinbin; TANG Shunlin; LI Zhonggen; WANG Shaofeng; LIANG Lian

    2004-01-01

    Since municipal wastes contain refuses with high mercury contents, incineration of municipal wastes becomes the major anthropogenic atmospheric mercury emission source. In China, landfills are however the main way to dispose of municipal wastes. Total gaseous mercury (TGM) concentrations in landfill gas of Gaoyan sanitary landfill located in suburb of Guiyang City were monitored using a high temporal resolved automated mercury analyzer, and mono-methylmercury (MMHg) and dimethylmercury (DMHg) concentrations in landfill gas were also measured using GC coupled with the cold vapor atomic fluorescence (CVAFS) method. Meanwhile, the TGM exchange fluxes between exposed waste and air and the soil surface of the landfill and air, were measured using low Hg blank quartz flux chamber coupled with high temporal resolved automated mercury analyzer technique. TGM concentrations in landfill gas from half year filling area averaged out at 665.52±291.25 ng/m3, which is comparable with TGM concentrations from flue gas of a small coal combustion boiler in Guiyang. The average MMHg and DMHg concentrations averaged out at 2.06±1.82 ng/m3 and 9.50±5.18 ng/m3, respectively. It is proven that mercury emission is the predominant process at the surfaces of both exposed wastes and soil of landfill. Landfills are not only TGM emission source, but also methylmercury emission source to the ambient air. There are two ways to emit mercury to the air from landfills, one is with the landfill gas through landfill gas duct, and the other through soil/air exchange. The Hg emission processes from landfills are controlled by meteorological parameters.

  15. Durability Challenges for Next Generation of Gas Turbine Engine Materials

    Science.gov (United States)

    Misra, Ajay K.

    2012-01-01

    Aggressive fuel burn and carbon dioxide emission reduction goals for future gas turbine engines will require higher overall pressure ratio, and a significant increase in turbine inlet temperature. These goals can be achieved by increasing temperature capability of turbine engine hot section materials and decreasing weight of fan section of the engine. NASA is currently developing several advanced hot section materials for increasing temperature capability of future gas turbine engines. The materials of interest include ceramic matrix composites with 1482 - 1648 C temperature capability, advanced disk alloys with 815 C capability, and low conductivity thermal barrier coatings with erosion resistance. The presentation will provide an overview of durability challenges with emphasis on the environmental factors affecting durability for the next generation of gas turbine engine materials. The environmental factors include gaseous atmosphere in gas turbine engines, molten salt and glass deposits from airborne contaminants, impact from foreign object damage, and erosion from ingestion of small particles.

  16. Product specific emissions from municipal solid waste landfills

    DEFF Research Database (Denmark)

    Nielsen, Per Henning; Hauschild, Michael Zwicky

    1998-01-01

    For the inventory analysis of environmental impacts associated with products in LCA there is a great need for estimates of emissions from waste products disposed at municipal solid waste landfills (product specific emissions). Since product specific emissions can not be calculated or measured...... directly at the landfills, they must be estimated by modelling of landfill processes. This paper presents a landfill model based on a large number of assumptions and approximations concerning landfill properties, waste product properties and characteristics of various kinds of environmental protection...... systems (e.g. landfill gas combustion units and leachate treatment units). The model is useful for estimation of emissions from waste products disposed in landfills and it has been made operational in the computer tool LCA-LAND presented in a following paper. In the model, waste products are subdivided...

  17. Product specific emissions from municipal solid waste landfills

    DEFF Research Database (Denmark)

    Nielsen, Per Henning; Hauschild, Michael Zwicky

    1998-01-01

    directly at the landfills, they must be estimated by modelling of landfill processes. This paper presents a landfill model based on a large number of assumptions and approximations concerning landfill properties, waste product properties and characteristics of various kinds of environmental protection...... systems (e.g. landfill gas combustion units and leachate treatment units). The model is useful for estimation of emissions from waste products disposed in landfills and it has been made operational in the computer tool LCA-LAND presented in a following paper. In the model, waste products are subdivided......For the inventory analysis of environmental impacts associated with products in LCA there is a great need for estimates of emissions from waste products disposed at municipal solid waste landfills (product specific emissions). Since product specific emissions can not be calculated or measured...

  18. Quantification of methane emissions from 15 Danish landfills using the mobile tracer dispersion method

    Energy Technology Data Exchange (ETDEWEB)

    Mønster, Jacob [Department of Environmental Engineering, Technical University of Denmark, Miljøvej – Building 113, DK-2800 Lyngby (Denmark); Samuelsson, Jerker, E-mail: jerker.samuelsson@fluxsense.se [Chalmers University of Technology/FluxSense AB, SE-41296 Göteborg (Sweden); Kjeldsen, Peter [Department of Environmental Engineering, Technical University of Denmark, Miljøvej – Building 113, DK-2800 Lyngby (Denmark); Scheutz, Charlotte, E-mail: chas@env.dtu.dk [Department of Environmental Engineering, Technical University of Denmark, Miljøvej – Building 113, DK-2800 Lyngby (Denmark)

    2015-01-15

    Highlights: • Quantification of whole landfill site methane emission at 15 landfills. • Multiple on-site source identification and quantification. • Quantified methane emission from shredder waste and composting. • Large difference between measured and reported methane emissions. - Abstract: Whole-site methane emissions from 15 Danish landfills were assessed using a mobile tracer dispersion method with either Fourier transform infrared spectroscopy (FTIR), using nitrous oxide as a tracer gas, or cavity ring-down spectrometry (CRDS), using acetylene as a tracer gas. The landfills were chosen to represent the different stages of the lifetime of a landfill, including open, active, and closed covered landfills, as well as those with and without gas extraction for utilisation or flaring. Measurements also included landfills with biocover for oxidizing any fugitive methane. Methane emission rates ranged from 2.6 to 60.8 kg h{sup −1}, corresponding to 0.7–13.2 g m{sup −2} d{sup −1}, with the largest emission rates per area coming from landfills with malfunctioning gas extraction systems installed, and the smallest emission rates from landfills closed decades ago and landfills with an engineered biocover installed. Landfills with gas collection and recovery systems had a recovery efficiency of 41–81%. Landfills where shredder waste was deposited showed significant methane emissions, with the largest emission from newly deposited shredder waste. The average methane emission from the landfills was 154 tons y{sup −1}. This average was obtained from a few measurement campaigns conducted at each of the 15 landfills and extrapolating to annual emissions requires more measurements. Assuming that these landfills are representative of the average Danish landfill, the total emission from Danish landfills were calculated at 20,600 tons y{sup −1}, which is significantly lower than the 33,300 tons y{sup −1} estimated for the national greenhouse gas inventory for

  19. Revisions to the hydrogen gas generation computer model

    Energy Technology Data Exchange (ETDEWEB)

    Jerrell, J.W.

    1992-08-31

    Waste Management Technology has requested SRTC to maintain and extend a previously developed computer model, TRUGAS, which calculates hydrogen gas concentrations within the transuranic (TRU) waste drums. TRUGAS was written by Frank G. Smith using the BASIC language and is described in the report A Computer Model of gas Generation and Transport within TRU Waste Drums (DP- 1754). The computer model has been partially validated by yielding results similar to experimental data collected at SRL and LANL over a wide range of conditions. The model was created to provide the capability of predicting conditions that could potentially lead to the formation of flammable gas concentrations within drums, and to assess proposed drum venting methods. The model has served as a tool in determining how gas concentrations are affected by parameters such as filter vent sizes, waste composition, gas generation values, the number and types of enclosures, water instrusion into the drum, and curie loading. The success of the TRUGAS model has prompted an interest in the program`s maintenance and enhancement. Experimental data continues to be collected at various sites on such parameters as permeability values, packaging arrangements, filter designs, and waste contents. Information provided by this data is used to improve the accuracy of the model`s predictions. Also, several modifications to the model have been made to enlarge the scope of problems which can be analyzed. For instance, the model has been used to calculate hydrogen concentrations inside steel cabinets containing retired glove boxes (WSRC-RP-89-762). The revised TRUGAS computer model, H2GAS, is described in this report. This report summarizes all modifications made to the TRUGAS computer model and provides documentation useful for making future updates to H2GAS.

  20. Revisions to the hydrogen gas generation computer model

    Energy Technology Data Exchange (ETDEWEB)

    Jerrell, J.W.

    1992-08-31

    Waste Management Technology has requested SRTC to maintain and extend a previously developed computer model, TRUGAS, which calculates hydrogen gas concentrations within the transuranic (TRU) waste drums. TRUGAS was written by Frank G. Smith using the BASIC language and is described in the report A Computer Model of gas Generation and Transport within TRU Waste Drums (DP- 1754). The computer model has been partially validated by yielding results similar to experimental data collected at SRL and LANL over a wide range of conditions. The model was created to provide the capability of predicting conditions that could potentially lead to the formation of flammable gas concentrations within drums, and to assess proposed drum venting methods. The model has served as a tool in determining how gas concentrations are affected by parameters such as filter vent sizes, waste composition, gas generation values, the number and types of enclosures, water instrusion into the drum, and curie loading. The success of the TRUGAS model has prompted an interest in the program's maintenance and enhancement. Experimental data continues to be collected at various sites on such parameters as permeability values, packaging arrangements, filter designs, and waste contents. Information provided by this data is used to improve the accuracy of the model's predictions. Also, several modifications to the model have been made to enlarge the scope of problems which can be analyzed. For instance, the model has been used to calculate hydrogen concentrations inside steel cabinets containing retired glove boxes (WSRC-RP-89-762). The revised TRUGAS computer model, H2GAS, is described in this report. This report summarizes all modifications made to the TRUGAS computer model and provides documentation useful for making future updates to H2GAS.

  1. Environmental assessment of solid waste landfilling technologies by means of LCA-modeling

    DEFF Research Database (Denmark)

    Manfredi, Simone; Christensen, Thomas Højlund

    2009-01-01

    -aerobic landfill) and assesses the influence of the active operations practiced on these performances. The environmental assessments have been performed by means of the LCA-based tool EASEWASTE, whereby the functional unit utilized for the LCA is “landfilling of 1 ton of wet household waste in a 10 m deep landfill...... should be taken to prevent leachate infiltration to groundwater and it is essential to collect and treat the generated leachate. The bioreactor technologies recirculate the collected leachate to enhance the waste degradation process. This allows the gas collection period to be reduced from 40 to 15 years......, although it does not lead to noticeable environmental benefits when considering a 100 years LCA-perspective. In order to more comprehensively understand the influence of the active operations (i.e., leachate recirculation, waste flushing and air injection) on the environmental performance, the time horizon...

  2. An Assessment of the Disposal of Petroleum Industry NORM in Nonhazardous Landfills

    Energy Technology Data Exchange (ETDEWEB)

    Arnish, John J.; Blunt, Deborah, L.; Haffenden, Rebecca A.; Herbert, Jennifer; Pfingston, Manjula; Smith, Karen P.; Williams, Gustavious P.

    1999-10-12

    In this study, the disposal of radium-bearing NORM wastes in nonhazardous landfills in accordance with the MDEQ guidelines was modeled to evaluate potential radiological doses and resultant health risks to workers and the general public. In addition, the study included an evaluation of the potential doses and health risks associated with disposing of a separate NORM waste stream generated by the petroleum industry--wastes containing lead-210 (Pb-210) and its progeny. Both NORM waste streams are characterized in Section 3 of this report. The study also included reviews of (1) the regulatory constraints applicable to the disposal of NORM in nonhazardous landfills in several major oil and gas producing states (Section 2) and (2) the typical costs associated with disposing of NORM, covering disposal options currently permitted by most state regulations as well as the nonhazardous landfill option (Section 4).

  3. Investigation of Productivity of Brown’s (HHO Gas Generator

    Directory of Open Access Journals (Sweden)

    Andrius Brazdžiūnas

    2017-01-01

    Full Text Available There were made tests of productivity of Brown’s gas generator using different potassium hydroxide (KOH concentration changing voltage and amperage. It is described experimental stand that is used to do researches and methodology of experiments performance. Brown’s gas production in electrolyser (electrolyser – the device that is going electrolysis to use stainless steel (AISI 316 electrodes. It was determined after researches that increasing the potassium hydroxide (KOH concentration in the solution and using the same amperage and voltage of the all concentration results are similar. The highest productivity 1.429 l/min was obtained by using a 120 A amperage and 15 V voltage.

  4. Phyto cover for Sanitary Landfill Sites: A brief review

    Directory of Open Access Journals (Sweden)

    Bhavya D. Shah

    2017-03-01

    Full Text Available Landfill gases (LFG are produced due to biodegradation of organic fraction of municipal solid waste (MSW when water comes in contact with buried wastes. The conventional clay cover is still practiced to mitigate the percolation of water in landfills in India. Gas extraction systems in landfill for gas collection are used but are much expensive. Thus, “Phytocapping” technique can be one of the alternatives to mitigate landfill gases and to minimize percolation of water into the landfill. Indian plants with locally available soil and municipal solid waste can be tested for the purpose of methane mitigation, heavy metals remediation from leachate. Methane oxidation due to vegetation can be observed compared to non-vegetated landfill. Root zone methane concentrations can be monitored for the plant species.

  5. Generation of synthesis gas by partial oxidation of natural gas in a gas turbine

    NARCIS (Netherlands)

    Cornelissen, R.; Tober, E.; Kok, J.B.W.; Meer, van der T.H.

    2006-01-01

    The application of partial oxidation in a gas turbine (PO-GT) in the production of synthesis gas for methanol production is explored. In PO-GT, methane is compressed, preheated, partial oxidized and expanded. For the methanol synthesis a 12% gain in thermal efficiency has been calculated for the PO-

  6. Generation of synthesis gas by partial oxidation of natural gas in a gas turbine

    NARCIS (Netherlands)

    Cornelissen, R.; Tober, E.; Kok, Jacobus B.W.; van der Meer, Theodorus H.

    2006-01-01

    The application of partial oxidation in a gas turbine (PO-GT) in the production of synthesis gas for methanol production is explored. In PO-GT, methane is compressed, preheated, partial oxidized and expanded. For the methanol synthesis a 12% gain in thermal efficiency has been calculated for the

  7. Landfilling: Environmental Issues

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Manfredi, Simone; Kjeldsen, Peter

    2011-01-01

    Waste disposed of in a landfill is by its nature different from the material found in the surroundings of the landfill and thereby the landfill may potentially affect the surrounding environment. This may be in terms of attracting or repelling flora and fauna from the area and through the emissio...

  8. Landfill leachate treatment in assisted landfill bioreactor

    Institute of Scientific and Technical Information of China (English)

    HE Pin-jing; QU Xian; SHAO Li-ming; LEE Duu-jong

    2006-01-01

    Landfill is the major disposal route of municipal solid waste(MSW) in most Asian countries. Leachate from landfill presents a strong wastewater that needs intensive treatment before discharge. Direct recycling was proposed as an effective alternative for leachate treatment by taking the landfill as a bioreactor. This process was proved not only considerably reducing the pollution potential of leachate, but also enhancing organic degradation in the landfill. However, as this paper shows, although direct leachate recycling was effective in landfilled MSW with low food waste fraction (3.5%, w/w), it failed in MSW containing 54% food waste, as normally noted in Asian countries. The initial acid stuck would inhibit methanogenesis to build up, hence strong leachate was yielded from landfill to threaten the quality of receiving water body. We demonstrated the feasibility to use an assisted bioreactor landfill, with a well-decomposed refuse layer as ex-situ anaerobic digester to reducing COD loading in leachate. By doing so, the refuse in simulated landfill column (2.3 m high) could be stabilized in 30 weeks while the COD in leachate reduced by 95%(61000 mg/L to 3000 mg/L). Meanwhile, the biogas production was considerably enhanced, signaling by the much greater amount and much higher methane content in the biogas.

  9. Continuous organic waste digester and methane gas generator

    Energy Technology Data Exchange (ETDEWEB)

    Araneta, V.A.

    1979-01-01

    A patent on the construction of a utility model of an industrial product of a continuous organic-waste digester and methane-gas generator is described. It comprises an airtight chamber to receive slurry of organic waste; a gas-water scrubber to purge carbon dioxide, odor-omitting gases and froth or scrum from newly formed methane gas evolving from said slurry of organic wastes; and two dually functioning slurry-feed and -discharge pipes connected to a reversible pump. It has one pipe with an opening at the base of an airtight chamber and the other pipe with up-ended openings below the fluid level of the slurry to be accumulated in the airtight chamber.

  10. Environmental impact assessment of leachate recirculation in landfill of municipal solid waste by comparing with evaporation and discharge (EASEWASTE)

    DEFF Research Database (Denmark)

    Xing, Wei; Lu, Wenjing; Zhao, Yan

    2013-01-01

    in leachate and the depositional ammonia from biogas. Moreover, the direct discharge of leachate may also result in ecotoxicity and human toxicity via water contaminated by heavy metals in leachate, with 3.96 PE and 11.64 PE respectively. The results also show that landfill gas is the main contributor...... of contaminants derived from waste can be stored in the landfill for long periods, with 11.69 person equivalent (PE) for stored ecotoxicity in water and 29.62 PE for stored ecotoxicity in soil, considered as potential risks of releasing to the environment someday. Meanwhile, impacts to ecotoxicity and human...... scenarios were modeled using EASEWASTE, comparing the strategies of leachate recirculation (with or without gas management), evaporation and discharge. In the current situation (Scenario A), a total of 280t of waste was generated and then transported to a conventional landfill for disposal. A number...

  11. Modeling acid-gas generation from boiling chloride brines

    Directory of Open Access Journals (Sweden)

    Sonnenthal Eric

    2009-11-01

    Full Text Available Abstract Background This study investigates the generation of HCl and other acid gases from boiling calcium chloride dominated waters at atmospheric pressure, primarily using numerical modeling. The main focus of this investigation relates to the long-term geologic disposal of nuclear waste at Yucca Mountain, Nevada, where pore waters around waste-emplacement tunnels are expected to undergo boiling and evaporative concentration as a result of the heat released by spent nuclear fuel. Processes that are modeled include boiling of highly concentrated solutions, gas transport, and gas condensation accompanied by the dissociation of acid gases, causing low-pH condensate. Results Simple calculations are first carried out to evaluate condensate pH as a function of HCl gas fugacity and condensed water fraction for a vapor equilibrated with saturated calcium chloride brine at 50-150°C and 1 bar. The distillation of a calcium-chloride-dominated brine is then simulated with a reactive transport model using a brine composition representative of partially evaporated calcium-rich pore waters at Yucca Mountain. Results show a significant increase in boiling temperature from evaporative concentration, as well as low pH in condensates, particularly for dynamic systems where partial condensation takes place, which result in enrichment of HCl in condensates. These results are in qualitative agreement with experimental data from other studies. Conclusion The combination of reactive transport with multicomponent brine chemistry to study evaporation, boiling, and the potential for acid gas generation at the proposed Yucca Mountain repository is seen as an improvement relative to previously applied simpler batch evaporation models. This approach allows the evaluation of thermal, hydrological, and chemical (THC processes in a coupled manner, and modeling of settings much more relevant to actual field conditions than the distillation experiment considered. The actual

  12. Modeling acid-gas generation from boiling chloride brines

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Guoxiang; Spycher, Nicolas; Sonnenthal, Eric; Steefel, Carl

    2009-11-16

    This study investigates the generation of HCl and other acid gases from boiling calcium chloride dominated waters at atmospheric pressure, primarily using numerical modeling. The main focus of this investigation relates to the long-term geologic disposal of nuclear waste at Yucca Mountain, Nevada, where pore waters around waste-emplacement tunnels are expected to undergo boiling and evaporative concentration as a result of the heat released by spent nuclear fuel. Processes that are modeled include boiling of highly concentrated solutions, gas transport, and gas condensation accompanied by the dissociation of acid gases, causing low-pH condensate. Simple calculations are first carried out to evaluate condensate pH as a function of HCl gas fugacity and condensed water fraction for a vapor equilibrated with saturated calcium chloride brine at 50-150 C and 1 bar. The distillation of a calcium-chloride-dominated brine is then simulated with a reactive transport model using a brine composition representative of partially evaporated calcium-rich pore waters at Yucca Mountain. Results show a significant increase in boiling temperature from evaporative concentration, as well as low pH in condensates, particularly for dynamic systems where partial condensation takes place, which result in enrichment of HCl in condensates. These results are in qualitative agreement with experimental data from other studies. The combination of reactive transport with multicomponent brine chemistry to study evaporation, boiling, and the potential for acid gas generation at the proposed Yucca Mountain repository is seen as an improvement relative to previously applied simpler batch evaporation models. This approach allows the evaluation of thermal, hydrological, and chemical (THC) processes in a coupled manner, and modeling of settings much more relevant to actual field conditions than the distillation experiment considered. The actual and modeled distillation experiments do not represent

  13. Detection and quantification of methane leakage from landfills

    Energy Technology Data Exchange (ETDEWEB)

    Ljungberg, Sven-Aake; Maartensson, Stig-Goeran (Univ. of Gaevle, Gaevle (Sweden)); Meijer, Jan-Erik; Rosqvist, Haakan (NSR AB, Helsingborg (Sweden))

    2009-03-15

    The purpose of this project was to detect gas leakage and to measure and quantify methane emission from landfills using modern remote sensing techniques. In this project, a handheld laser instrument and an IR camera were used. The overall objective was to develop cost-effective methods for detecting and quantifying methane emissions from landfills. There are many methods available for measuring the methane concentration in air, both from close-up and from long distances. Combined with the use of a tracer gas, the methane emission from entire landfills can be measured relatively accurately. A number of methods are used to detect leakage from parts of landfill surfaces, but there are few methods for quantifying leakage from sub-zones. Field measurements with the laser instrument and the IR camera were carried out at seven Swedish landfills and two landfills in France. The investigated surfaces at the Swedish landfills were divided into different zones, such as top surface, slope, crest and toe of slope. The field measurements in France were taken over entire landfills. The methane emission varied between the different landfills in the project, and also between the different landfill zones. The results from repeated field measurements indicated that a landfill with a final cap and a successful gas recovery system produces barely measurable emissions. The weak points at a landfill are generally slopes, including crests and toes of slopes. Where the covering of the waste is inadequate, leakage often occurs at lift joints and in areas where waste protrudes through the cover. Other weak points are deficiencies in the gas recovery system. Leachate systems can lead landfill gas and thereby cause methane leakage. Along with wind velocity and variations in atmospheric pressure, moisture content in the ground is an important factor that affects methane emissions from landfill surfaces. Results from field measurements of the same feature/surface at different points in time and

  14. Oxygen rich gas generator design and performance analysis

    Science.gov (United States)

    Gloyer, P. W.; Knuth, W. H.; Crawford, R. A.

    1993-01-01

    The present oxygen-rich combustion research investigates oxygen gas generator concepts. The theoretical and modeling aspects of a selected concept are presented, together with a refined concept resulting from the findings of the study. This investigation examined a counter-flow gas generator design for O2/H2 mass ratios of 100-200, featuring a near-stoichiometric combustion zone followed by downstream mixing. The critical technologies required to develop a performance model are analyzed and include the following: (1) oxygen flow boiling; (2) two-phase oxygen flow heat transfer; (3) film-cooling in the combustion zone; (4) oxygen-rich combustion with hydrogen; and (5) mixing and dilution.

  15. Landfill methane emission mitigation – How to construct and document a full‐scale biocover system

    DEFF Research Database (Denmark)

    Kjeldsen, Peter; Scheutz, Charlotte

    2014-01-01

    Landfills receiving organic wastes produce biogas (landfill gas – LFG) containing methane (CH4). Landfills are significant sources of methane, which contributes to climate change. As an alternative to gas utilization systems or as a follow‐on technology when a gas utilization system gets non...... rate can be obtained in soils, compost and other materials, high enough to significant reduce the methane emission from landfills. The process has been scaled up by DTU Environment to a full‐scale implemented technology at two Danish landfills. Now the Danish government has decided to establish bio...

  16. Composition and source identification of deposits forming in landfill gas (LFG) engines and effect of activated carbon treatment on deposit composition.

    Science.gov (United States)

    Sevimoğlu, Orhan; Tansel, Berrin

    2013-10-15

    Compositions of deposits forming on engines parts operated with landfill gas (LFG) were analyzed. The deposit compositions were compared before and after the installation of activated carbon system for treatment of LFG. Deposits forming on the spark plugs had significantly higher levels of calcium, chromium, and nickel in comparison to those forming on the engine heads. The LFG contained about 9.5 ± 0.4 mg/m(3) total siloxanes, majority of which were octamethylcyclotetrasiloxane (D4) (5.0 ± 0.2 mg/m(3)), decamethylcyclopentasiloxane (D5) (2.9 ± 0.1 mg/m(3)) and hexamethyldisiloxane (L2) (1.6 ± 0.1 mg/m(3)). The samples collected from the engine heads before the activated carbon treatment of LFG had significantly high levels of silicon (149,400 ± 89,900 mg/kg) as well as calcium (70,840 ± 17,750 mg/kg), sulfur (42,500 ± 11,500 mg/kg), and zinc (22,300 ± 7200 mg/kg). After the activated carbon treatment, silicon levels decreased significantly; however, deposits had higher sulfur content (104,560 ± 68,100 mg/kg) indicating that the activated carbon released some sulfur during treatment. The analyses indicate that zinc and calcium originated from the additives in the lube oil while lead, aluminum, copper, nickel, iron, chromium were due to the engine wear.

  17. Achieving "Final Storage Quality" of municipal solid waste in pilot scale bioreactor landfills.

    Science.gov (United States)

    Valencia, R; van der Zon, W; Woelders, H; Lubberding, H J; Gijzen, H J

    2009-01-01

    Entombed waste in current sanitary landfills will generate biogas and leachate when physical barriers fail in the future, allowing the intrusion of moisture into the waste mass contradicting the precepts of the sustainability concept. Bioreactor landfills are suggested as a sustainable option to achieve Final Storage Quality (FSQ) status of waste residues; however, it is not clear what characteristics the residues should have in order to stop operation and after-care monitoring schemes. An experiment was conducted to determine the feasibility to achieve FSQ status (Waste Acceptance Criteria of the European Landfill Directive) of residues in a pilot scale bioreactor landfill. The results of the leaching test were very encouraging due to their proximity to achieve the proposed stringent FSQ criterion after 2 years of operation. Furthermore, residues have the same characteristics of alternative waste stabilisation parameters (low BMP, BOD/COD ratio, VS content, SO4(2-)/Cl- ratio) established by other researchers. Mass balances showed that the bioreactor landfill simulator was capable of practically achieving biological stabilisation after 2 years of operation, while releasing approximately 45% of the total available (organic and inorganic) carbon and nitrogen into the liquid and gas phases.

  18. Gas turbine powerhouse the development of the power generation gas turbine at BBC - ABB - Alstom

    CERN Document Server

    Eckardt, Dietrich

    2014-01-01

    This book tells the story of the power generation gas turbine from the perspective of one of the leading companies in the field over a period of nearly 100 years, written by an engineer. Especially in times of imminent global economic crises it appears to be worthwhile to reflect on real economic values based on engineering ingenuity and enduring management of technological leadership.

  19. Landfilling: Concepts and Challenges

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Scharff, H.; Hjelmar, O.

    2011-01-01

    Landfilling of waste historically has been the main management route for waste, and in many parts of the world it still is. Landfills have developed from open polluting dumps to modern highly engineered facilities with sophisticated control measures and monitoring routines. However, in spite of all...... new approaches and technological advancement the landfill still is a long lasting accumulation of waste in the environment. Much of current landfill design and technology has been introduced as a reaction to problems encountered at actual landfills. The solution was in many cases sought in isolation...... to understand the concepts, the processes and the long-term aspects of landfilling. This chapter describes the main conceptual aspects of landfilling. The historical development is presented and key issues of time frames, mass balances and technical approaches are discussed. The environmental issues...

  20. Effects of oxygen cover gas and NaOH dilution on gas generation in tank 241-SY-101 waste

    Energy Technology Data Exchange (ETDEWEB)

    Person, J.C.

    1996-05-30

    Laboratory studies are reported of gas generation in heated waste from tank 241-SY-101. The rates of gas generation and the compositions of product gas were measured. Three types of tests are compared. The tests use: undiluted waste, waste diluted by a 54% addition of 2.5 M NaOH, and undiluted waste with a reactive cover gas of 30% Oxygen in He. The gas generation rate is reduced by dilution, increased by higher temperatures (which determines activation energies), and increased by reactions of Oxygen (these primarily produce H{sub 2}). Gases are generated as reduction products oxidation of organic carbon species by nitrite and oxygen.

  1. Gas-turbine expander power generating systems for internal needs of compressor stations of gas-main pipelines

    Science.gov (United States)

    Shimanov, A. A.; Biryuk, V. V.; Sheludko, L. P.; Shabanov, K. Yu.

    2017-08-01

    In the framework of this paper, there have been analyzed power station building methods to construct a power station for utilities for gas-main pipelines compressor stations. The application efficiency of turbo expanders in them to expand the power gas of compressor stations' gas compressor units has been shown. New schemes for gas-turbine expander power generating systems have been proposed.

  2. Leakage Currents and Gas Generation in Advanced Wet Tantalum Capacitors

    Science.gov (United States)

    Teverovsky, Alexander

    2015-01-01

    Currently, military grade, established reliability wet tantalum capacitors are among the most reliable parts used for space applications. This has been achieved over the years by extensive testing and improvements in design and materials. However, a rapid insertion of new types of advanced, high volumetric efficiency capacitors in space systems without proper testing and analysis of degradation mechanisms might increase risks of failures. The specifics of leakage currents in wet electrolytic capacitors is that the conduction process is associated with electrolysis of electrolyte and gas generation resulting in building up of internal gas pressure in the parts. The risk associated with excessive leakage currents and increased pressure is greater for high value advanced wet tantalum capacitors, but it has not been properly evaluated yet. In this work, in Part I, leakages currents in various types of tantalum capacitors have been analyzed in a wide range of voltages, temperatures, and time under bias. Gas generation and the level of internal pressure have been calculated in Part II for different case sizes and different hermeticity leak rates to assess maximal allowable leakage currents. Effects related to electrolyte penetration to the glass seal area have been studied and the possibility of failures analyzed in Part III. Recommendations for screening and qualification to reduce risks of failures have been suggested.

  3. REFINEMENT OF PRODUCER GAS GENERATED FROM BIOMASS GASIFIER

    Directory of Open Access Journals (Sweden)

    L. KUMARARAJA

    2016-01-01

    Full Text Available Producer gas (PG generated from biomass by thermo-chemical gasification process has been proved to be a reliable and renewable substitute for petroleum fuels to drive internal combustion engines. The gasification technology has been developed well and also commercialised. However, more technological advancements must happen in the refining of PG. Generally, the refinement is confined to the removal of tar and particulates from PG before supplying it to the engines. This paper proposes to remove additionally carbon dioxide and water vapour from PG so that its heating value can be increased and faster combustion can be attained in the engine cylinder. In this direction, the various CO2 removal technologies which are currently employed for combustion flue gas, natural gas and biogas have been first studied in detail. They are: physical absorption in solvents, chemical absorption by reagents, adsorption, membrane separation and refrigeration. In the present research, a batch of experiments has been conducted by washing PG with water to absorb CO2 physically and in a separate batch of experiments PG has been treated with aqueous ammonia to absorb CO2 chemically. For both experiments, the PG was generated by a downdraft biomass gasifier fed with wood pieces. The CO2 reduction obtained was 10.9% in physical absorption by water and 95% in chemical absorption by aqueous ammonia. Along with the reduction of CO2 and H2O from PG, the tar and particulates content of PG could also be reduced by absorption method.

  4. Tailored ramp wave generation in gas gun experiments

    Directory of Open Access Journals (Sweden)

    Cotton Matthew

    2015-01-01

    Full Text Available Gas guns are traditionally used as platforms to introduce a planar shock wave to a material using plate impact methods, generating states on the Hugoniot. The ability to deliver a ramp wave to a target during a gas gun experiment enables access to different regions of the equation-of-state surface, making it a valuable technique for characterising material behaviour. Previous techniques have relied on the use of multi-material impactors to generate a density gradient, which can be complex to manufacture. In this paper we describe the use of an additively manufactured steel component consisting of an array of tapered spikes which can deliver a ramp wave over ∼ 2 μs. The ability to tailor the input wave by varying the component design is discussed, an approach which makes use of the design freedom offered by additive manufacturing techniques to rapidly iterate the spike profile. Results from gas gun experiments are presented to evaluate the technique, and compared with 3D hydrodynamic simulations.

  5. Generation and characterization of gas bubbles in liquid metals

    Energy Technology Data Exchange (ETDEWEB)

    Eckert, S.; Gerbeth, G.; Witke, W.

    1996-06-01

    There is an ongoing research performed in the RCR on local transport phenomena in turbulent liquid metal (LM) duct flows exposed to external magnetic fields. In this context so-called MHD flow phenomena can be observed, which are unknown in usual hydraulic engineering. The field of interest covers also the influence of magnetic fields on the behaviour of liquid metal - gas mixtures. Profound knowledge on these LMMHD two-phase flow plays an important role in a variety of technological applications, in particular, in the design of Liquid-Metal MHD generators or for several metallurgical processes employing gas-stirred reactors. However, the highly empirical nature of two-phase flow analysis gives little hope for the prediction of MHD two-phase flows without extensive experimental data. A summary is given about the authors research activities focussing on two directions: (a) Momentum transfer between gas and liquid metal in a bubbly flow regime to investigate the influence of the external magnetic field on the velocity slip ration S (b) Peculiarities of the MHD turbulence to use small gas bubbles as local tracers in order to study the turbulent mass transfer.

  6. Department of Energy power generation programs for natural gas

    Energy Technology Data Exchange (ETDEWEB)

    Bajura, R.A.

    1995-04-01

    The U.S. Department of Energy (DOE) is sponsoring two major programs to develop high efficiency, natural gas fueled power generation technologies. These programs are the Advanced Turbine Systems (ATS) Program and the Fuel Cell Program. While natural gas is gaining acceptance in the electric power sector, the improved technology from these programs will make gas an even more attractive fuel, particularly in urban areas where environmental concerns are greatest. Under the auspices of DOE`s Office of Fossil Energy (DOE/FE) and Office of Energy Efficiency and Renewable Energy (DOE/EE), the 8-year ATS Program is developing and will demonstrate advanced gas turbine power systems for both large central power systems and smaller industrial-scale systems. The large-scale systems will have efficiencies significantly greater than 60 percent, while the industrial-scale systems will have efficiencies with at least an equivalent 15 percent increase over the best 1992-vintage technology. The goal is to have the system ready for commercial offering by the year 2000.

  7. Initial results of detected methane emissions from landfills in the Los Angeles Basin during the COMEX campaign by the Methane Airborne MAPper (MAMAP) instrument and a greenhouse gas in-situ analyser

    Science.gov (United States)

    Krautwurst, Sven; Gerilowski, Konstantin; Kolyer, Richard; Jonsson, Haflidi; Krings, Thomas; Horstjann, Markus; Leifer, Ira; Vigil, Sam; Buchwitz, Michael; Schüttemeyer, Dirk; Fladeland, Matthew M.; Burrows, John P.; Bovensmann, Heinrich

    2015-04-01

    Methane (CH4) is the second most important anthropogenic greenhouse gas beside carbon dioxide (CO2). Significant contributors to the global methane budget are fugitive emissions from landfills. Due to the growing world population, it is expected that the amount of waste and, therefore, waste disposal sites will increase in number and size in parts of the world, often adjacent growing megacities. Besides bottom-up modelling, a variety of ground based methods (e.g., flux chambers, trace gases, radial plume mapping, etc.) have been used to estimate (top-down) these fugitive emissions. Because landfills usually are large, sometimes with significant topographic relief, vary temporally, and leak/emit heterogeneously across their surface area, assessing total emission strength by ground-based techniques is often difficult. In this work, we show how airborne based remote sensing measurements of the column-averaged dry air mole fraction of CH4 can be utilized to estimate fugitive emissions from landfills in an urban environment by a mass balance approach. Subsequently, these emission rates are compared to airborne in-situ horizontal cross section measurements of CH4 taken within the planetary boundary layer (PBL) upwind and downwind of the landfill at different altitudes immediately after the remote sensing measurements were finished. Additional necessary parameters (e.g., wind direction, wind speed, aerosols, dew point temperature, etc.) for the data inversion are provided by a standard instrumentation suite for atmospheric measurements aboard the aircraft, and nearby ground-based weather stations. These measurements were part of the CO2 and Methane EXperiment (COMEX), which was executed during the summer 2014 in California and was co-funded by the European Space Agency (ESA) and the National Aeronautics and Space Administration (NASA). The remote sensing measurements were taken by the Methane Airborne MAPper (MAMAP) developed and operated by the University of Bremen and

  8. Quantification of methane emissions from 15 Danish landfills using the mobile tracer dispersion method

    DEFF Research Database (Denmark)

    Mønster, Jacob; Samuelsson, Jerker; Kjeldsen, Peter

    2015-01-01

    biocover installed. Landfills with gas collection and recovery systems had a recovery efficiency of 41-81%. Landfills where shredder waste was deposited showed significant methane emissions, with the largest emission from newly deposited shredder waste. The average methane emission from the landfills...

  9. Landfilling of waste: accounting of greenhouse gases and global warming contributions

    DEFF Research Database (Denmark)

    Manfredi, Simone; Tonini, Davide; Christensen, Thomas Højlund

    2009-01-01

    Accounting of greenhouse gas (GHG) emissions from waste landfilling is summarized with the focus on processes and technical data for a number of different landfilling technologies: open dump (which was included as the worst-case-scenario), conventional landfills with flares and with energy recove...

  10. Total system evaluation of gas generation and migration in the radioactive waste repository

    Energy Technology Data Exchange (ETDEWEB)

    Ando, K.; Fujiwara, A.; Tokuyama, S.; Adachi, T.; Saeki, T. [Radioactive Waste Management Funding and Research Center, Tokyo (Japan); Vomvoris, S. [NAGRA, Baden (Switzerland); Fukudome, K. [Kobe Steel Ltd. (Japan); Shimmura, A. [Obayashi Corp., Shinagawa Intercity Tower, Minato-ku (Japan)

    2001-07-01

    The carbon steel used in the nuclear waste repository under reductive condition reacts with ground water and generates hydrogen gas. It might accumulate and degrade performance of the Engineered Barrier System (EBS). It is highly important to evaluate the influence of gas generation and migration under the repository-like environment. Therefore, the Gas Generation Test is performed in Gas Evaluation Facility (GEF) in Japan and the Gas Migration Test (GMT) is performed in Nagra Grimsel Test Site (GTS) in Switzerland. (author)

  11. Improvements on cool gas generators and their application in space propulsion systems

    NARCIS (Netherlands)

    Sanders, H.M.; Schuurbiers, C.A.H.; Vandeberg, R.J.

    2014-01-01

    Cool Gas Generators are an innovative means to store gas which can be used in propulsion and pressurization systems but also for inflatable structures and terrestrial applications. In Cool Gas Generators, the gas is stored chemically, without pressure or leakage and with a long life time without mai

  12. Study of compressor systems for a gas-generator engine

    Science.gov (United States)

    Sather, Bernard I; Tauschek, Max J

    1950-01-01

    Various methods of providing compressor-capacity and pressure-ratio control in the gas-generator type of compound engine over a range of altitudes from sea level to 50,000 feet are presented. The analytical results indicate that the best method of control is that in which the first stage of compression is carried out in a variable-speed supercharger driven by a hydraulic slip coupling. The constant-speed second stage could be either a mixed-flow rotary compressor or a piston-type compressor. A variable-area turbine nozzle is shown to be unnecessary for cruising operation of the engine.

  13. Differences in volatile methyl siloxane (VMS) profiles in biogas from landfills and anaerobic digesters and energetics of VMS transformations.

    Science.gov (United States)

    Tansel, Berrin; Surita, Sharon C

    2014-11-01

    The objectives of this study were to compare the types and levels of volatile methyl siloxanes (VMS) present in biogas generated in the anaerobic digesters and landfills, evaluate the energetics of siloxane transformations under anaerobic conditions, compare the conditions in anaerobic digesters and municipal solid waste (MSW) landfills which result in differences in siloxane compositions. Biogas samples were collected at the South District Wastewater Treatment Plant and South Dade Landfill in Miami, Florida. In the digester gas, D4 and D5 comprised the bulk of total siloxanes (62% and 27%, respectively) whereas in the landfill gas, the bulk of siloxanes were trimethylsilanol (TMSOH) (58%) followed by D4 (17%). Presence of high levels of TMSOH in the landfill gas indicates that methane utilization may be a possible reaction mechanism for TMSOH formation. The free energy change for transformation of D5 and D4 to TMSOH either by hydrogen or methane utilization are thermodynamically favorable. Either hydrogen or methane should be present at relatively high concentrations for TMSOH formation which explains the high levels present in the landfill gas. The high bond energy and bond distance of the Si-O bond, in view of the atomic sizes of Si and O atoms, indicate that Si atoms can provide a barrier, making it difficult to break the Si-O bonds especially for molecules with specific geometric configurations such as D4 and D5 where oxygen atoms are positioned inside the frame formed by the large Si atoms which are surrounded by the methyl groups.

  14. Advanced Combustion Systems for Next Generation Gas Turbines

    Energy Technology Data Exchange (ETDEWEB)

    Joel Haynes; Jonathan Janssen; Craig Russell; Marcus Huffman

    2006-01-01

    Next generation turbine power plants will require high efficiency gas turbines with higher pressure ratios and turbine inlet temperatures than currently available. These increases in gas turbine cycle conditions will tend to increase NOx emissions. As the desire for higher efficiency drives pressure ratios and turbine inlet temperatures ever higher, gas turbines equipped with both lean premixed combustors and selective catalytic reduction after treatment eventually will be unable to meet the new emission goals of sub-3 ppm NOx. New gas turbine combustors are needed with lower emissions than the current state-of-the-art lean premixed combustors. In this program an advanced combustion system for the next generation of gas turbines is being developed with the goal of reducing combustor NOx emissions by 50% below the state-of-the-art. Dry Low NOx (DLN) technology is the current leader in NOx emission technology, guaranteeing 9 ppm NOx emissions for heavy duty F class gas turbines. This development program is directed at exploring advanced concepts which hold promise for meeting the low emissions targets. The trapped vortex combustor is an advanced concept in combustor design. It has been studied widely for aircraft engine applications because it has demonstrated the ability to maintain a stable flame over a wide range of fuel flow rates. Additionally, it has shown significantly lower NOx emission than a typical aircraft engine combustor and with low CO at the same time. The rapid CO burnout and low NOx production of this combustor made it a strong candidate for investigation. Incremental improvements to the DLN technology have not brought the dramatic improvements that are targeted in this program. A revolutionary combustor design is being explored because it captures many of the critical features needed to significantly reduce emissions. Experimental measurements of the combustor performance at atmospheric conditions were completed in the first phase of the program

  15. Landfill Top Covers

    DEFF Research Database (Denmark)

    Scheutz, Charlotte; Kjeldsen, Peter

    2011-01-01

    is landscaped in order to fit into the surrounding area/environment or meet specific plans for the final use of the landfill. To fulfill the above listed requirements landfill covers are often multicomponent systems which are placed directly on top of the waste. The top cover may be placed immediately after...... the landfill section has been filled or several years later depending on the settlement patterns. Significant differential settlements may disturb the functioning of the top cover. The specific design of the cover system depends on the type of waste landfilled (municipal, hazardous, or inert waste...... however, top covers may be the only environmental protection measure. In some landfill regulations (for instance the Subtitle D landfills receiving municipal solid waste in the USA) it is required to minimize infiltration into the waste layers. Therefore top covers containing liner components...

  16. Design Optimization of Gas Generator Hybrid Propulsion Boosters

    Science.gov (United States)

    Weldon, Vincent; Phillips, Dwight; Fink, Larry

    1990-01-01

    A methodology used in support of a study for NASA/MSFC to optimize the design of gas generator hybrid propulsion booster for uprating the National Space Transportation System (NSTS) is presented. The objective was to compare alternative configurations for this booster approach, optimizing each candidate concept on different bases, in order to develop data for a trade table on which a final decision was based. The methodology is capable of processing a large number of independent and dependent variables, adjusting the overall subsystems characteristics to arrive at a best compromise integrated design to meet various specific optimization criteria subject to selected constraints. For each system considered, a detailed weight statement was generated along with preliminary cost and reliability estimates.

  17. Counter-Rotatable Fan Gas Turbine Engine with Axial Flow Positive Displacement Worm Gas Generator

    Science.gov (United States)

    Giffin, Rollin George (Inventor); Murrow, Kurt David (Inventor); Fakunle, Oladapo (Inventor)

    2014-01-01

    A counter-rotatable fan turbine engine includes a counter-rotatable fan section, a worm gas generator, and a low pressure turbine to power the counter-rotatable fan section. The low pressure turbine maybe counter-rotatable or have a single direction of rotation in which case it powers the counter-rotatable fan section through a gearbox. The gas generator has inner and outer bodies having offset inner and outer axes extending through first, second, and third sections of a core assembly. At least one of the bodies is rotatable about its axis. The inner and outer bodies have intermeshed inner and outer helical blades wound about the inner and outer axes and extending radially outwardly and inwardly respectively. The helical blades have first, second, and third twist slopes in the first, second, and third sections respectively. A combustor section extends through at least a portion of the second section.

  18. Safe Management of Waste Generated during Shale Gas Operations

    Science.gov (United States)

    Kukulska-Zając, Ewa; Król, Anna; Holewa-Rataj, Jadwiga

    2017-04-01

    Exploration and exploitation of hydrocarbon deposits, regardless of their type, are connected with the generation of waste, which may have various environmental effects. Such wastes may pose a serious risk to the surrounding environment and public health because they usually contain numerous potentially toxic chemicals. Waste associated with exploration and exploitation of unconventional hydrocarbon deposits is composed of a mixture of organic and inorganic materials, the qualitative and quantitative composition of which changes widely over time, depending on numerous factors. As a result the proper characteristic of this type of waste is very important. Information gained from detailed chemical analyses of drilling chemicals, drilling wastes, and flowback water can be used to manage shale gas-related wastes more appropriately, to develop treatment methods, to store the waste, and assess the potential environmental and health risk. The following paper will focus mainly on the results of research carried out on waste samples coming from the unconventional hydrogen exploration sites. Additionally, regulatory frameworks applicable to the management of wastes produced during this type of works will be discussed. The scope of research concerning physicochemical parameters for this type of wastes will also be presented. The presented results were obtained during M4ShaleGas project realization. The M4ShaleGas project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement no. 640715.

  19. Kinetics of hydrocarbon generation for Well Yingnan 2 gas reservoir,Tarim Basin,CHina

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Well Yingnan 2,an important exploratory well in the east of Tarim Basin,yields high commercial oil and gas flow in Jurassic.Natural gas components and carbon isotopic composition indicate that it belongs to sapropel type gas.Because this region presents many suits of hydrocarbon source rocks,there are some controversies that natural gases were generated from kerogen gas or crude oil cracking gas at present.By using the kinetics of hydrocarbon generation and carbon isotope,natural gas of Well Yingnan 2 is composed mainly of crude oil cracking gas,about 72%,it is generated from secondary kerogen gas of Cambrian-Lower Ordovician source rock and crude oil cracking gas of Mid-Upper Ordovician oil reservoir.The main oil and gas filling time is 65 Ma later in the Jurassic gas reservoir of Well Yingnan 2,so the gas reservoir belongs to late accumulation and continuous filling type.

  20. CSIR wins R1 million gas generator contract

    Energy Technology Data Exchange (ETDEWEB)

    1989-01-01

    The Division of Energy Technology, CSIR, has signed a R1 million contract with Slagment (Pty) Ltd for the supply, installation and commissioning during the first half of 1989 of a fluidized-bed hot gas generator. The contract was won on selected tender. A demonstration plant was built during 1984 in Pretoria West and funded by the Development of Mineral and Energy Affairs, to demonstrate to industry the ability of fluidized-bed technology to burn discard coal, thus reducing energy costs. It has been in operation for more than 20 000 hours and has demonstrated that it can successfully operate on coals with up to 70% ash and 8% sulfur content as well as on duff coal and char with a fines content of up to 50% less than 2mm diameter. The importance of offering a solution to the serious problem of stockpiling local inferior coals and the prospect of developing local expertise in the new, emerging technology, gave the research project the required support. The following are discussed: fluidization, fluidized beds and combustion of coal, fluidized bed boilers burning coal, fluidized-bed hot gas generator burning coal; advantages of fluidized-bed combustors, and applications. 2 figs.

  1. Aerobic landfill bioreactor

    Science.gov (United States)

    Hudgins, Mark P; Bessette, Bernard J; March, John; McComb, Scott T.

    2000-01-01

    The present invention includes a method of decomposing municipal solid waste (MSW) within a landfill by converting the landfill to aerobic degradation in the following manner: (1) injecting air via the landfill leachate collection system (2) injecting air via vertical air injection wells installed within the waste mass; (3) applying leachate to the waste mass using a pressurized drip irrigation system; (4) allowing landfill gases to vent; and (5) adjusting air injection and recirculated leachate to achieve a 40% to 60% moisture level and a temperature between 120.degree. F. and 140.degree. F. in steady state.

  2. Estimation of future methane production from Hellenic landfills

    Energy Technology Data Exchange (ETDEWEB)

    Tsatsarelis, T.; Karagiannidis, A. [Aristotle Univ., Thessaloniki (Greece). Lab. of Heat Transfer and Environmental Engineering

    2009-07-15

    Organic waste decomposition leads to the production of Landfill Gas (LFG). LFG mainly consists of methane (CH{sub 4}) and carbon dioxide (CO{sub 2}). It is common understanding now that LFG should be considered either as a significant source of pollution and risk (if migrating uncontrollably to the air and ground), or as a significant source of renewable energy (if extracted and processed accordingly). There are two possible solutions for dealing with LFG emissions. In the case of low methane ratios, LFG should be extracted and flared or oxidized in biofilters. On the other hand, in the case of high methane content, LFG becomes an evidently valuable energy resource, as it is then able to sustain the fuelling of engines producing electricity and thermal energy. More specifically, it can be used as a supplementary or primary fuel to increase the production of electric power, as a pipeline quality gas and vehicle fuel, or even as a supply of heat and carbon dioxide for greenhouses and various industrial processes. Technologies that utilize LFG include internal combustion engines, gas turbines, fuel cells and boiler systems. The main objective of this research was to predict expected methane generation in Hellenic sanitary landfills, in order to evaluate its potential for energy production and to ensure health and safety in and around these sites on the long term. The study was performed for the period 2008--2028 with the use of a multi-phase model and included a sensitivity analysis in order to determine the impact of certain waste parameters. In this context, two 'extreme' reference scenarios were formulated and assessed, one anticipating fulfillment of the EU landfill directive (which sets limits to the amount of biodegradable and packaging materials to be deposited in sanitary landfills) whereas a second (do-nothing scenario) assuming no such timely compliance. The model used here for methane estimation is a multi-phase model developed by the Norwegian

  3. Contribution of individual waste fractions to the environmental impacts from landfilling of municipal solid waste.

    Science.gov (United States)

    Manfredi, Simone; Tonini, Davide; Christensen, Thomas H

    2010-03-01

    A number of LCA-based studies have reported on the environmental performance of landfilling of mixed waste, but little is known about the relative contributions of individual waste fractions to the overall impact potentials estimated for the mixed waste. In this paper, an empirical model has been used to estimate the emissions to the environment from landfilling of individual waste fractions. By means of the LCA-model EASEWASTE, the emissions estimated have been used to quantify how much of the overall impact potential for each impact category is to be attributed to the individual waste fractions. Impact potentials are estimated for 1 tonne of mixed waste disposed off in a conventional landfill with bottom liner, leachate collection and treatment and gas collection and utilization for electricity generation. All the environmental aspects are accounted for 100 years after disposal and several impact categories have been considered, including standard categories, toxicity-related categories and groundwater contamination. Amongst the standard and toxicity-related categories, the highest potential impact is estimated for human toxicity via soil (HTs; 12 mPE/tonne). This is mostly caused by leaching of heavy metals from ashes (e.g. residues from roads cleaning and vacuum cleaning bags), batteries, paper and metals. On the other hand, substantial net environmental savings are estimated for the categories Global Warming (GW; -31 mPE/tonne) and Eco-Toxicity in water chronic (ETwc; -53 mPE/tonne). These savings are mostly determined by the waste fractions characterized by a high content of biogenic carbon (paper, organics, other combustible waste). These savings are due to emissions from energy generation avoided by landfill gas utilization, and by the storage of biogenic carbon in the landfill due to incomplete waste degradation.

  4. Environmental impact assessment of leachate recirculation in landfill of municipal solid waste by comparing with evaporation and discharge (EASEWASTE).

    Science.gov (United States)

    Xing, Wei; Lu, Wenjing; Zhao, Yan; Zhang, Xu; Deng, Wenjing; Christensen, Thomas H

    2013-02-01

    In some arid regions where landfill produces minimal amount of leachate, leachate recirculation is suggested as a cost-effective option. However, its long-term impacts to environment remain disputed. For the purpose of revealing the environmental impacts of leachate recirculation in landfill, four scenarios were modeled using EASEWASTE, comparing the strategies of leachate recirculation (with or without gas management), evaporation and discharge. In the current situation (Scenario A), a total of 280 t of waste was generated and then transported to a conventional landfill for disposal. A number of contaminants derived from waste can be stored in the landfill for long periods, with 11.69 person equivalent (PE) for stored ecotoxicity in water and 29.62 PE for stored ecotoxicity in soil, considered as potential risks of releasing to the environment someday. Meanwhile, impacts to ecotoxicity and human toxicity in surface water, and those to groundwater, present relatively low levels. In Scenario B, leachate evaporation in a collecting pool has minimal impacts on surface water. However, this strategy significantly impacts groundwater (1055.16 PE) because of the potential infiltration of leachate, with major contaminants of As, ammonia, and Cd. A number of ions, such as Cl(-), Mg(2+), and Ca(2+), may also contaminate groundwater. In Scenario C, the direct discharge of leachate to surface water may result in acidification (2.71 PE) and nutrient enrichment (2.88 PE), primarily attributed to soluble ammonia in leachate and the depositional ammonia from biogas. Moreover, the direct discharge of leachate may also result in ecotoxicity and human toxicity via water contaminated by heavy metals in leachate, with 3.96 PE and 11.64 PE respectively. The results also show that landfill gas is the main contributor to global warming and photochemical ozone formation due to methane emission. In Scenario D, landfill gas flaring was thus be modeled and proven to be efficient for reducing

  5. Are closed landfills free of CH_{4} emissions? A case study of Arico's landfill, Tenerife, Canary Islands

    Science.gov (United States)

    Barrancos, José; Cook, Jenny; Phillips, Victoria; Asensio-Ramos, María; Melián, Gladys; Hernández, Pedro A.; Pérez, Nemesio M.

    2016-04-01

    Landfills are authentic chemical and biological reactors that introduce in the environment a wide amount of gas pollutants (CO2, CH4, volatile organic compounds, etc.) and leachates. Even after years of being closed, a significant amount of landfill gas could be released to the atmosphere through the surface in a diffuse form, also known as non-controlled emission. The study of the spatial-temporal distribution of diffuse emissions provides information of how a landfill degassing takes place. The main objective of this study was to estimate the diffuse uncontrolled emission of CH4 into the atmosphere from the closed Arico's landfill (0.3 km2) in Tenerife Island, Spain. To do so, a non-controlled biogenic gas emission survey of nearly 450 sampling sites was carried out during August 2015. Surface gas sampling and surface landfill CO2 efflux measurements were carried out at each sampling site by means of a portable non-dispersive infrared spectrophotometer (NDIR) model LICOR Li800 following the accumulation chamber method. Landfill gases, CO2 and CH4, were analyzed using a double channel VARIAN 4900 micro-GC. The CH4 efflux was computed combining CO2 efflux and CH4/CO2 ratio in the landfill's surface gas. To quantify the total CH4 emission, CH4 efflux contour map was constructed using sequential Gaussian simulation (sGs) as interpolation method. The total diffuse CH4 emission was estimated in 2.2 t d-1, with CH4 efflux values ranging from 0-922 mg m-2 d-1. This type of studies provides knowledge of how a landfill degasses and serves to public and private entities to establish effective systems for extraction of biogas. This aims not only to achieve higher levels of controlled gas release from landfills resulting in a higher level of energy production but also will contribute to minimize air pollution caused by them.

  6. Natural gas power generation: interruptible gas distribution network regulation; Geracao termoeletrica a gas natural: regulacao do segmento interruptivel de distribuicao de gas canalizado

    Energy Technology Data Exchange (ETDEWEB)

    Paula, Claudio Paiva de; Kann, Zevi [Agencia Reguladora de Saneamento e Energia do Estado de Sao Paulo (ARSESP), SP (Brazil)

    2008-07-01

    The paper relates studies regarding the natural gas distribution network interruptible branch. This new service can be appropriate for thermal power generation on flexible dispatch mode, as 'take or pay' contracts surplus jobs. The paper indicates no regulatory restraints in an interruptible network implantation. The final conclusion is that interruptible contracts can be an improvement on the distribution business and certainly can accommodate a suitable demand and supply volumes in the long-term gas market balance. (author)

  7. The new Waste Law: Challenging opportunity for future landfill operation in Indonesia.

    Science.gov (United States)

    Meidiana, Christia; Gamse, Thomas

    2011-01-01

    The Waste Law No. 18/2008 Article 22 and 44 require the local governments to run environmentally sound landfill. Due to the widespread poor quality of waste management in Indonesia, this study aimed to identify the current situation by evaluating three selected landfills based on the ideal conditions of landfill practices, which are used to appraise the capability of local governments to adapt to the law. The results indicated that the local governments have problems of insufficient budget, inadequate equipment, uncollected waste and unplanned future landfill locations. All of the selected landfills were partially controlled landfills with open dumping practices predominating. In such inferior conditions the implementation of sanitary landfill is not necessarily appropriate. The controlled landfill is a more appropriate solution as it offers lower investment and operational costs, makes the selection of a new landfill site unnecessary and can operate with a minimum standard of infrastructure and equipment. The sustainability of future landfill capacity can be maintained by utilizing the old landfill as a profit-oriented landfill by implementing a landfill gas management or a clean development mechanism project. A collection fee system using the pay-as-you-throw principle could increase the waste income thereby financing municipal solid waste management.

  8. PERFORMA OKSIDASI METAN PADA REAKTOR KONTINYU DENGAN PENINGKATAN KETEBALAN LAPISAN BIOCOVER LANDFILL

    Directory of Open Access Journals (Sweden)

    Opy Kurniasari

    2013-11-01

    Full Text Available PERFORMANCE OF METHANE OXIDATION IN CONTINUOUS REACTOR BY BIOCOVER LANDFILL FILM THICKNESS IMPROVEMENT. Municipal solid waste (MSW handling in Indonesia is currently highly dependent on landfilling at the final disposal facility (TPA, which generally operated in layer-by-layer basis, allowing the anaerobic (absent of oxygen process. This condition will certainly generate biogas in the form of methane (CH4 and CO2. Methane is a greenhouse gas with a global warming potential greater than CO2, and can absorb infrared radiation 23 times more efficient than CO2 in the period of over 100 years. One way that can be done to reduce methane gas from landfills that escape into nature is to oxidize methane by utilizing landfill cover material (biocover as methane-oxidizing microorganism media. Application of compost as landfill cover material is a low-cost approach to reduce emissions so are suitable for developing countries. The compost used in this study was compost landfill mining, which is degraded naturally in landfill. The purpose of this study was to evaluate the ability of biocover to oxidize the methane on a certain layer thickness with a continuous flow conditions. Three column reactors were used, which were made of flexy glass measuring 70 cm in high and 15 cm in diameter. The methane flowed from the bottom of the reactor continuously at a flow rate of 5 ml/minute. The columns were filled with biocover compost landfill mining with layer thickness of 5, 25, 35 and 60 cm. The results showed that the thicker layer of biocover, the higher the efficiency of methane oxidation. The oxidation efficiency obtained in each layer thickness of 15, 25, 35 and 60 cm was 56.43%, 63.69%, 74.58% and 80, 03% respectively, with the rate of oxidation of 0.29 mol m-2 d-1 and the fraction of oxidation of 99%. The oxidation result was supported by the identification of bacteria isolated in this experiment, namely metanotrophic bacteria that have the ability to oxidize

  9. BIOMASS GASIFICATION AND POWER GENERATION USING ADVANCED GAS TURBINE SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    David Liscinsky

    2002-10-20

    A multidisciplined team led by the United Technologies Research Center (UTRC) and consisting of Pratt & Whitney Power Systems (PWPS), the University of North Dakota Energy & Environmental Research Center (EERC), KraftWork Systems, Inc. (kWS), and the Connecticut Resource Recovery Authority (CRRA) has evaluated a variety of gasified biomass fuels, integrated into advanced gas turbine-based power systems. The team has concluded that a biomass integrated gasification combined-cycle (BIGCC) plant with an overall integrated system efficiency of 45% (HHV) at emission levels of less than half of New Source Performance Standards (NSPS) is technically and economically feasible. The higher process efficiency in itself reduces consumption of premium fuels currently used for power generation including those from foreign sources. In addition, the advanced gasification process can be used to generate fuels and chemicals, such as low-cost hydrogen and syngas for chemical synthesis, as well as baseload power. The conceptual design of the plant consists of an air-blown circulating fluidized-bed Advanced Transport Gasifier and a PWPS FT8 TwinPac{trademark} aeroderivative gas turbine operated in combined cycle to produce {approx}80 MWe. This system uses advanced technology commercial products in combination with components in advanced development or demonstration stages, thereby maximizing the opportunity for early implementation. The biofueled power system was found to have a levelized cost of electricity competitive with other new power system alternatives including larger scale natural gas combined cycles. The key elements are: (1) An Advanced Transport Gasifier (ATG) circulating fluid-bed gasifier having wide fuel flexibility and high gasification efficiency; (2) An FT8 TwinPac{trademark}-based combined cycle of approximately 80 MWe; (3) Sustainable biomass primary fuel source at low cost and potentially widespread availability-refuse-derived fuel (RDF); (4) An overall integrated

  10. Intelligent Bioreactor Management Information System (IBM-IS) for Mitigation of Greenhouse Gas Emissions

    Energy Technology Data Exchange (ETDEWEB)

    Paul Imhoff; Ramin Yazdani; Don Augenstein; Harold Bentley; Pei Chiu

    2010-04-30

    Methane is an important contributor to global warming with a total climate forcing estimated to be close to 20% that of carbon dioxide (CO2) over the past two decades. The largest anthropogenic source of methane in the US is 'conventional' landfills, which account for over 30% of anthropogenic emissions. While controlling greenhouse gas emissions must necessarily focus on large CO2 sources, attention to reducing CH4 emissions from landfills can result in significant reductions in greenhouse gas emissions at low cost. For example, the use of 'controlled' or bioreactor landfilling has been estimated to reduce annual US greenhouse emissions by about 15-30 million tons of CO2 carbon (equivalent) at costs between $3-13/ton carbon. In this project we developed or advanced new management approaches, landfill designs, and landfill operating procedures for bioreactor landfills. These advances are needed to address lingering concerns about bioreactor landfills (e.g., efficient collection of increased CH4 generation) in the waste management industry, concerns that hamper bioreactor implementation and the consequent reductions in CH4 emissions. Collectively, the advances described in this report should result in better control of bioreactor landfills and reductions in CH4 emissions. Several advances are important components of an Intelligent Bioreactor Management Information System (IBM-IS).

  11. Geologic and hydrologic data for the municipal solid waste landfill facility, U.S. Army Air Defense Artillery Center and Fort Bliss, El Paso County, Texas

    Science.gov (United States)

    Abeyta, Cynthia G.; Frenzel, P.F.

    1999-01-01

    Geologic and hydrologic data for the Municipal Solid Waste Landfill Facility on the U.S. Army Air Defense Artillery Center and Fort Bliss in El Paso County, Texas, were collected by the U.S. Geological Survey in cooperation with the U.S. Department of the Army. The 106.03-acre landfill has been in operation since January 1974. The landfill contains household refuse, Post solid wastes, bulky items, grass and tree trimmings from family housing, refuse from litter cans, construction debris, classified waste (dry), dead animals, asbestos, and empty oil cans. The depth of the filled areas is about 30 feet and the cover, consisting of locally derived material, is 2 to 3 feet thick. Geologic and hydrologic data were collected at or adjacent to the landfill during (1) drilling of 10 30- to 31-foot boreholes that were completed with gas-monitoring probes, (2) drilling of a 59-foot borehole, (3) drilling of a 355-foot borehole that was completed as a ground-water monitoring well, and (4) in situ measurements made on the landfill cover. After completion, the gas- monitoring probes were monitored on a quarterly basis (1 year total) for gases generated by the landfill. Water samples were collected from the ground-water monitoring well for chemical analysis. Data collection is divided into two elements: geologic data and hydrologic data. Geologic data include lithologic descriptions of cores and cuttings, geophysical logs, soil- gas and ambient-air analyses, and chemical analyses of soil. Hydrologic data include physical properties, total organic carbon, and pH of soil and sediment samples; soil-water chloride and soil-moisture analyses; physical properties of the landfill cover; measurements of depth to ground water; and ground-water chemical analyses. Interpretation of data is not included in this report.

  12. Modelling biogas production of solid waste: application of the BGP model to a synthetic landfill

    Science.gov (United States)

    Rodrigo-Ilarri, Javier; Segura-Sobrino, Francisco

    2013-04-01

    Production of biogas as a result of the decomposition of organic matter included on solid waste landfills is still an issue to be understood. Reports on this matter are rarely included on the engineering construction projects of solid waste landfills despite it can be an issue of critical importance while operating the landfill and after its closure. This paper presents an application of BGP (Bio-Gas-Production) model to a synthetic landfill. The evolution in time of the concentrations of the different chemical compounds of biogas is studied. Results obtained show the impact on the air quality of different management alternatives which are usually performed in real landfills.

  13. Full Scale Bioreactor Landfill for Carbon Sequestration and Greenhouse Emission Control

    Energy Technology Data Exchange (ETDEWEB)

    Ramin Yazdani; Jeff Kieffer; Kathy Sananikone; Don Augenstein

    2005-03-30

    The Yolo County Department of Planning and Public Works constructed a full-scale bioreactor landfill as a part of the Environmental Protection Agency's (EPA) Project XL program to develop innovative approaches for carbon sequestration and greenhouse emission control. The overall objective was to manage landfill solid waste for rapid waste decomposition and maximum landfill gas generation and capture for carbon sequestration and greenhouse emission control. Waste decomposition is accelerated by improving conditions for either the aerobic or anaerobic biological processes and involves circulating controlled quantities of liquid (leachate, groundwater, gray water, etc.), and, in the aerobic process, large volumes of air. The first phase of the project entailed the construction of a 12-acre module that contained a 6-acre anaerobic cell, a 3.5-acre anaerobic cell, and a 2.5-acre aerobic cell at the Yolo County Central Landfill near Davis, California. The cells were highly instrumented to monitor bioreactor performance. Liquid addition commenced in the 3.5-acre anaerobic cell and the 6-acre anaerobic cell. Construction of the 2.5-acre aerobic cell and biofilter has been completed. The current project status and preliminary monitoring results are summarized in this report.

  14. FULL SCALE BIOREACTOR LANDFILL FOR CARBON SEQUESTRATION AND GREENHOUSE EMISSION CONTROL

    Energy Technology Data Exchange (ETDEWEB)

    Ramin Yazdani; Jeff Kieffer; Heather Akau

    2002-01-01

    The Yolo County Department of Planning and Public Works is constructing a full-scale bioreactor landfill as a part of the Environmental Protection Agency's (EPA) Project XL program to develop innovative approaches while providing superior environmental protection. The overall objective is to manage landfill solid waste for rapid waste decomposition, maximum landfill gas generation and capture, and minimum long-term environmental consequences. Waste decomposition is accelerated by improving conditions for either the aerobic or anaerobic biological processes and involves circulating controlled quantities of liquid (leachate, groundwater, gray water, etc.), and, in the aerobic process, large volumes of air. The first phase of the project entails the construction of a 12-acre module that contains a 6-acre anaerobic cell, a 3.5-acre anaerobic cell, and a 2.5-acre aerobic cell at the Yolo County Central Landfill near Davis, California. The cells are highly instrumented to monitor bioreactor performance. The current project status and preliminary monitoring results are summarized in this report.

  15. FULL SCALE BIOREACTOR LANDFILL FOR CARBON SEQUESTRATION AND GREENHOUSE EMISSION CONTROL

    Energy Technology Data Exchange (ETDEWEB)

    Ramin Yazdani; Jeff Kieffer; Heather Akau

    2003-12-01

    The Yolo County Department of Planning and Public Works is constructing a full-scale bioreactor landfill as a part of the Environmental Protection Agency's (EPA) Project XL program to develop innovative approaches for carbon sequestration and greenhouse emission control. The overall objective is to manage landfill solid waste for rapid waste decomposition and maximum landfill gas generation and capture for carbon sequestration and greenhouse emission control. Waste decomposition is accelerated by improving conditions for either the aerobic or anaerobic biological processes and involves circulating controlled quantities of liquid (leachate, groundwater, gray water, etc.), and, in the aerobic process, large volumes of air. The first phase of the project entails the construction of a 12-acre module that contains a 6-acre anaerobic cell, a 3.5-acre anaerobic cell, and a 2.5-acre aerobic cell at the Yolo County Central Landfill near Davis, California. The cells are highly instrumented to monitor bioreactor performance. Liquid addition has commenced in the 3.5-acre anaerobic cell and the 6-acre anaerobic cell. Construction of the 2.5-acre aerobic cell and biofilter has been completed. The remaining task to be completed is to test the biofilter prior to operation, which is currently anticipated to begin in January 2004. The current project status and preliminary monitoring results are summarized in this report.

  16. FULL SCALE BIOREACTOR LANDFILL FOR CARBON SEQUESTRATION AND GREENHOUSE EMISSION CONTROL

    Energy Technology Data Exchange (ETDEWEB)

    Ramin Yazdani; Jeff Kieffer; Heather Akau

    2002-02-01

    The Yolo County Department of Planning and Public Works is constructing a full-scale bioreactor landfill as a part of the Environmental Protection Agency's (EPA) Project XL program to develop innovative approaches while providing superior environmental protection. The overall objective is to manage landfill solid waste for rapid waste decomposition, maximum landfill gas generation and capture, and minimum long-term environmental consequences. Waste decomposition is accelerated by improving conditions for either the aerobic or anaerobic biological processes and involves circulating controlled quantities of liquid (leachate, groundwater, gray water, etc.), and, in the aerobic process, large volumes of air. The first phase of the project entails the construction of a 12-acre module that contains a 6-acre anaerobic cell, a 3.5-acre anaerobic cell, and a 2.5-acre aerobic cell at the Yolo County Central Landfill near Davis, California. The cells are highly instrumented to monitor bioreactor performance. The current project status and preliminary monitoring results are summarized in this report.

  17. FULL SCALE BIOREACTOR LANDFILL FOR CARBON SEQUESTRATION AND GREENHOUSE EMISSION CONTROL

    Energy Technology Data Exchange (ETDEWEB)

    Ramin Yazdani; Jeff Kieffer; Heather Akau

    2003-05-01

    The Yolo County Department of Planning and Public Works is constructing a full-scale bioreactor landfill as a part of the Environmental Protection Agency's (EPA) Project XL program to develop innovative approaches for carbon sequestration and greenhouse emission control. The overall objective is to manage landfill solid waste for rapid waste decomposition and maximum landfill gas generation and capture for carbon sequestration and greenhouse emission control. Waste decomposition is accelerated by improving conditions for either the aerobic or anaerobic biological processes and involves circulating controlled quantities of liquid (leachate, groundwater, gray water, etc.), and, in the aerobic process, large volumes of air. The first phase of the project entails the construction of a 12-acre module that contains a 6-acre anaerobic cell, a 3.5-acre anaerobic cell, and a 2.5-acre aerobic cell at the Yolo County Central Landfill near Davis, California. The cells are highly instrumented to monitor bioreactor performance. Construction is complete on the 3.5-acre anaerobic cell and liquid addition has commenced. Construction of the 2.5-acre aerobic cell is nearly complete with only the biofilter remaining and construction of the west-side 6-acre anaerobic cell is nearly complete with only the liquid addition system remaining. The current project status and preliminary monitoring results are summarized in this report.

  18. FULL SCALE BIOREACTOR LANDFILL FOR CARBON SEQUESTRATION AND GREENHOUSE EMISSION CONTROL

    Energy Technology Data Exchange (ETDEWEB)

    Ramin Yazdani; Jeff Kieffer; Heather Akau

    2002-04-01

    The Yolo County Department of Planning and Public Works is constructing a full-scale bioreactor landfill as a part of the Environmental Protection Agency's (EPA) Project XL program to develop innovative approaches while providing superior environmental protection. The overall objective is to manage landfill solid waste for rapid waste decomposition, maximum landfill gas generation and capture, and minimum long-term environmental consequences. Waste decomposition is accelerated by improving conditions for either the aerobic or anaerobic biological processes and involves circulating controlled quantities of liquid (leachate, groundwater, gray water, etc.), and, in the aerobic process, large volumes of air. The first phase of the project entails the construction of a 12-acre module that contains a 6-acre anaerobic cell, a 3.5-acre anaerobic cell, and a 2.5-acre aerobic cell at the Yolo County Central Landfill near Davis, California. The cells are highly instrumented to monitor bioreactor performance. Construction is complete on the 3.5 acre anaerobic cell and liquid addition has commenced. Construction of the 2.5 acre aerobic cell is nearly complete with only the blower station and biofilter remaining. Waste placement and instrumentation installation is ongoing in the west-side 6-acre anaerobic cell. The current project status and preliminary monitoring results are summarized in this report.

  19. FULL SCALE BIOREACTOR LANDFILL FOR CARBON SEQUESTRATION AND GREENHOUSE EMISSION CONTROL

    Energy Technology Data Exchange (ETDEWEB)

    Ramin Yazdani; Jeff Kieffer; Heather Akau

    2003-08-01

    The Yolo County Department of Planning and Public Works is constructing a full-scale bioreactor landfill as a part of the Environmental Protection Agency's (EPA) Project XL program to develop innovative approaches for carbon sequestration and greenhouse emission control. The overall objective is to manage landfill solid waste for rapid waste decomposition and maximum landfill gas generation and capture for carbon sequestration and greenhouse emission control. Waste decomposition is accelerated by improving conditions for either the aerobic or anaerobic biological processes and involves circulating controlled quantities of liquid (leachate, groundwater, gray water, etc.), and, in the aerobic process, large volumes of air. The first phase of the project entails the construction of a 12-acre module that contains a 6-acre anaerobic cell, a 3.5-acre anaerobic cell, and a 2.5-acre aerobic cell at the Yolo County Central Landfill near Davis, California. The cells are highly instrumented to monitor bioreactor performance. Liquid addition has commenced in the 3.5-acre anaerobic cell and the 6-acre anaerobic cell. Construction of the 2.5-acre aerobic cell is nearly complete with only the biofilter remaining and is scheduled to be complete by the end of August 2003. The current project status and preliminary monitoring results are summarized in this report.

  20. FULL SCALE BIOREACTOR LANDFILL FOR CARBON SEQUESTRATION AND GREENHOUSE EMISSION CONTROL

    Energy Technology Data Exchange (ETDEWEB)

    Ramin Yazdani; Jeff Kieffer; Heather Akau

    2002-08-01

    The Yolo County Department of Planning and Public Works is constructing a full-scale bioreactor landfill as a part of the Environmental Protection Agency's (EPA) Project XL program to develop innovative approaches for carbon sequestration and greenhouse emission control. The overall objective is to manage landfill solid waste for rapid waste decomposition and maximum landfill gas generation and capture for carbon sequestration and greenhouse emission control. Waste decomposition is accelerated by improving conditions for either the aerobic or anaerobic biological processes and involves circulating controlled quantities of liquid (leachate, groundwater, gray water, etc.), and, in the aerobic process, large volumes of air. The first phase of the project entails the construction of a 12-acre module that contains a 6-acre anaerobic cell, a 3.5-acre anaerobic cell, and a 2.5-acre aerobic cell at the Yolo County Central Landfill near Davis, California. The cells are highly instrumented to monitor bioreactor performance. Construction is complete on the 3.5-acre anaerobic cell and liquid addition has commenced. Construction of the 2.5 acre aerobic cell is nearly complete with only the blower station and biofilter remaining. Waste placement and instrumentation installation is ongoing in the west-side 6-acre anaerobic cell. The current project status and preliminary monitoring results are summarized in this report.

  1. FULL SCALE BIOREACTOR LANDFILL FOR CARBON SEQUESTRATION AND GREENHOUSE EMISSION CONTROL

    Energy Technology Data Exchange (ETDEWEB)

    Ramin Yazdani; Jeff Kieffer; Heather Akau

    2003-12-01

    The Yolo County Department of Planning and Public Works is constructing a full-scale bioreactor landfill as a part of the Environmental Protection Agency's (EPA) Project XL program to develop innovative approaches for carbon sequestration and greenhouse emission control. The overall objective is to manage landfill solid waste for rapid waste decomposition and maximum landfill gas generation and capture for carbon sequestration and greenhouse emission control. Waste decomposition is accelerated by improving conditions for either the aerobic or anaerobic biological processes and involves circulating controlled quantities of liquid (leachate, groundwater, gray water, etc.), and, in the aerobic process, large volumes of air. The first phase of the project entails the construction of a 12-acre module that contains a 6-acre anaerobic cell, a 3.5-acre anaerobic cell, and a 2.5-acre aerobic cell at the Yolo County Central Landfill near Davis, California. The cells are highly instrumented to monitor bioreactor performance. Liquid addition has commenced in the 3.5-acre anaerobic cell and the 6-acre anaerobic cell. Construction of the 2.5-acre aerobic cell and biofilter has been completed. The remaining task to be completed is to test the biofilter prior to operation, which is currently anticipated to begin in January 2004. The current project status and preliminary monitoring results are summarized in this report.

  2. Gas dilution system using critical flow Venturi nozzles for generating primary trace-moisture standards in multiple gas species

    Science.gov (United States)

    Amano, Minami; Abe, Hisashi

    2017-02-01

    Gas dilution systems are commonly used to generate calibration gas mixtures for secondary gas standards. However, if a gas dilution system is used to generate gas mixtures for primary trace-moisture standards in multiple gas species, difficulty arises; flow control with relative stability of better than 0.009% is required although the relative uncertainty of the best gas flow meter to date is around 0.3%. In this study, we developed a novel gas dilution system using critical flow Venturi nozzles to address this problem. The developed dilution system can measure and control the flow rates of gases in the range of approximately 0.05 l min-1 to 7 l min-1 (when converted to those measured at 101 325 Pa and 273.15 K) with relative stability of better than 0.007%. Using the dilution system, we developed a magnetic suspension balance/diffusion-tube humidity generator capable of generating trace moisture in N2 in the range of approximately 10 nmol mol-1 to 5 µmol mol-1 in amount fraction. The accuracy of the generated trace-moisture standard was verified by measurement with cavity ring-down spectroscopy.

  3. ETV/ESTCP Demonstration Plan - Demonstration and Verification of a Turbine Power Generation System Utilizing Renewable Fuel: Landfill Gas

    Science.gov (United States)

    This Test and Quality Assurance Plan (TQAP) provides data quality objections for the success factors that were validated during this demonstration include energy production, emissions and emission reductions compared to alternative systems, economics, and operability, including r...

  4. Results of Laboratory and Industrial Tests of Periodic-Type Gas Generators

    Science.gov (United States)

    Karp, I. N.; P‧yanykh, K. E.; Antoshchuk, T. A.; Lysenko, A. A.

    2015-05-01

    Results of laboratory and industrial tests of periodic-type gas generators burning various solid biofuels have been presented. The tests were carried out with the aim of obtaining producer gas which could totally or partly replace natural gas in power equipment burning gaseous fuel. The energy and environmental characteristics of a boiler unit burning a mixture of producer gas and natural gas have been assessed.

  5. Metathesis in the generation of low-temperature gas in marine shales

    OpenAIRE

    Jarvie Daniel M; Mango Frank D

    2010-01-01

    Abstract The recent report of low-temperature catalytic gas from marine shales took on additional significance with the subsequent disclosure of natural gas and low-temperature gas at or near thermodynamic equilibrium in methane, ethane, and propane. It is important because thermal cracking, the presumed source of natural gas, cannot generate these hydrocarbons at equilibrium nor can it bring them to equilibrium over geologic time. The source of equilibrium and the source of natural gas are e...

  6. Risk assessment of an old landfill regarding the potential of gaseous emissions--a case study based on bioindication, FT-IR spectroscopy and thermal analysis.

    Science.gov (United States)

    Tintner, Johannes; Smidt, Ena; Böhm, Katharina; Matiasch, Lydia

    2012-12-01

    Risk assessment of two sections (I and II) of an old landfill (ALH) in Styria (Austria) in terms of reactivity of waste organic matter and the related potential of gaseous emissions was performed using conventional parameters and innovative tools to verify their effectiveness in practice. The ecological survey of the established vegetation at the landfill surface (plant sociological relevés) indicated no relevant emissions over a longer period of time. Statistical evaluation of conventional parameters reveals that dissolved organic carbon (DOC), respiration activity (RA(4)), loss of ignition (LOI) and total inorganic carbon (TIC) mostly influence the variability of the gas generation sum (GS(21)). According to Fourier Transform Infrared (FT-IR) spectral data and the results of the classification model the reactivity potential of the investigated sections is very low which is in accordance with the results of plant sociological relevés and biological tests. The interpretation of specific regions in the FT-IR spectra was changed and adapted to material characteristics. Contrary to mechanically-biologically treated (MBT) materials, where strong aliphatic methylene bands indicate reactivity, they are rather assigned to the C-H vibrations of plastics in old landfill materials. This assumption was confirmed by thermal analysis and the characteristic heat flow profile of plastics containing landfill samples. Therefore organic carbon contents are relatively high compared to other stable landfills as shown by a prediction model for TOC contents based on heat flow profiles and partial least squares regression (PLS-R). The stability of the landfill samples, expressed by the relation of CO(2) release and enthalpies, was compared to unreactive landfills, archeological samples, earthlike materials and hardly degradable organic matter. Due to the material composition and the aging process the landfill samples are located between hardly degradable, but easily combustible

  7. Investigation of gas generation in regenerative fuel cells by low-energy X-rays

    Science.gov (United States)

    Selamet, Omer Faruk; Deevanhxay, Phengxay; Tsushima, Shohji; Hirai, Shuichiro

    2015-11-01

    Gas generation and discharge behaviors in an operating regenerative fuel cell (RFC) are investigated using low-energy X-ray radiography. In situ visualization at high spatial and temporal resolution reveal dynamic and inhomogeneous behaviors of the gas generation in the membrane electrode assembly (MEA) in the RFC. Temporal and spatial variation of the gas thickness in the MEA is quantitatively discussed and shows an intermittent and periodic discharge processes of the gas generated by electrolysis, suggesting that the reaction sites in the catalyst layer and the discharging path of gas bubbles are well established in the MEA for the electrolysis. Larger gas accumulation and discharge in the gas diffusion layer (GDL) under the ribs are identified in comparison with those under the channels, which is attributed to the relatively longer path for accumulated gas under the ribs to be discharged into the flow channels.

  8. Microbial reduction of methane emissions. Subproject 1: Development of a biofilter system for the degradation of methane, odours and trace gases for actively vented landfills. Subproject 2: Development of a biofilter system for the degradation of methane, odours and trace gases for passively vented landfills. Subproject 3: Planning, development and realisation of medium and large scale biofilter plants at active and passive gas drainage systems. Final report; Mikrobielle Verminderung von Methanemissionen. Teilvorhaben 1: Entwicklung eines Biofilterverfahrens zum Abbau von Methan, Geruechen und Spurengasen bei der aktiven Deponieentgasung. Teilvorhaben 2: Entwicklung eines Biofilterverfahrens zum Abbau von Methan, Geruechen und Spurengasen bei der passiven Deponieentgasung. Teilvorhaben 3: Planung, Entwicklung und Realisation halb- und grosstechnischer Biofilteranlagen an aktiven und passiven Entgasungssystemen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Stegmann, R.; Streese, J.; Dammann, Bernd; Gebert, J.; Groengroeft, A.; Miehlich, G.; Schulze, H.; Berndt, M.

    2003-07-01

    Old landfills may emit considerable amounts of methane, carbon dioxide and trace gases. However, gas flow rate and methane content are usually too low for energetic utilization or flaring of the landfill gas. Microbial degradation is considered an alternative treatment for the reduction of methane emissions from those sites. The project aimed in the investigation of the suitability of actively vented biofilters for this purpose and the collection of operational experience and dimensioning data for large scale applications of the process. Different experimental plants were operated in laboratory scale (filter volume: 60 L) and container scale (filter volume: 4 m{sup 3}). The laboratory scale plant was operated with synthetic methane, whereas the container scale plant was set up at an old landfill and operated with real landfill gas. For each plant, the gas was diluted with ambient air prior to feeding into the closed biofilters, thus sufficient oxygen for methane oxidation was present throughout the filter material. At first, fine-grained compost as biofilter material was investigated. A biofilter unit of 15 m{sup 3} size containing porous clay pellets as filter material was integrated into the recultivation layer of a Hamburg harbour sludge landfill. The parameters of landfill gas emission as well as the abiotic parameters of biofilter operation were monitored by a high-resolution automatic data collection system and gas distribution and gas emissions via the biofilter surface measured regularly. In addition, microbiological laboratory studies and studies concerning physical questions of biofilter operations were conducted. (orig.)

  9. DESIGN, FABRICATION, AND TESTING OF AN ADVANCED, NON-POLLUTING TURBINE DRIVE GAS GENERATOR

    Energy Technology Data Exchange (ETDEWEB)

    Unknown

    2002-03-31

    The objectives of this report period were to complete the development of the Gas Generator design, which was done; fabricate and test of the non-polluting unique power turbine drive gas Gas Generator, which has been postponed. Focus during this report period has been to complete the brazing and bonding necessary to fabricate the Gas Generator hardware, continue making preparations for fabricating and testing the Gas Generator, and continuing the fabrication of the Gas Generator hardware and ancillary hardware in preparation for the test program. Fabrication is more than 95% complete and is expected to conclude in early May 2002. the test schedule was affected by relocation of the testing to another test supplier. The target test date for hot fire testing is now not earlier than June 15, 2002.

  10. Effectiveness of the Vertical Gas Ventilation Pipes for Promoting Waste Stabilization in Post-Closure Phase

    Directory of Open Access Journals (Sweden)

    Yasumasa Tojo

    2015-06-01

    Full Text Available To make inside of the municipal solid waste (MSW landfill aerobic as much as possible is thought to be preferable for promoting waste stabilization, reducing pollutant's load in leachate, minimizing greenhouse gas emission and shortening post-closure-care period. In Japan, installation of semi-aerobic landfill structure has widely spread in order to promote waste stabilization in MSW landfill from 1980s. In semi-aerobic landfill structure, outlet of main leachate collection pipe is opened to atmosphere. Heat generated by aerobic degradation of waste causes natural convection and natural aeration arises from the outlet of leachate collection pipe to the gas vents. It is so-called stack effect. This air flow is thought to be effective for purifying leachate flowing through drainage layer and leachate collection pipes. And it is also thought to be contributing to expanding aerobic region in waste layer in landfill. Recently, measures attempting the promotion of waste stabilization are taken at several landfills at where stabilization of waste delays, in which many vertical gas vents are newly installed and close structure to semi-aerobic landfill is created. However, in many cases, these gas vents are not connected to leachate collection pipes. Many vertical gas vents are just installed without scientific proof regarding whether they can contribute for waste stabilization. In this study, how such installation of gas vents is effective for waste stabilization and aerobization of waste layer was discussed by numerical analysis. In numerical analysis, heat transfer, gas movement by pressure, gas diffusion, biological degradation of organic matter, and heat generation by biodegradation were taken into account. Simulations were carried out by using the general purpose simulator of finite element method. Three types of landfill structure were assumed. As the results, the following information were obtained. In dig-down type landfill, installation of gas

  11. Application of High Intensity THz Pulses for Gas High Harmonic Generation

    CERN Document Server

    Balogh, Emeric; Hebling, János; Dombi, Péter; Farkas, Győző; Varjú, Katalin

    2013-01-01

    The main effects of an intense THz pulse on gas high harmonic generation are studied via trajectory analysis on the single atom level. Spectral and temporal modifications to the generated radiation are highlighted.

  12. Methods of Sensing Land Pollution from Sanitary Landfills

    Science.gov (United States)

    Nosanov, Myron Ellis; Bowerman, Frank R.

    1971-01-01

    Major cities are congested and large sites suitable for landfill development are limited. Methane and other gases are produced at most sanitary landfills and dumps. These gases may migrate horizontally and vertically and have caused fatalities. Monitoring these gases provides data bases for design and construction of safe buildings on and adjacent to landfills. Methods of monitoring include: (1) a portable combustible gas indicator; and (2) glass flasks valved to allow simultaneous exhaust of the flask and aspiration of the sample into the flask. Samples are drawn through tubing from probes as deep as twenty-five feet below the surface.

  13. Performance of bioreactor landfill with waste mined from a dumpsite.

    Science.gov (United States)

    Karthikeyan, Obuli P; Swati, M; Nagendran, R; Joseph, Kurian

    2007-12-01

    Emissions from landfills via leachate and gas are influenced by state and stability of the organic matter in the solid waste and the environmental conditions within the landfill. This paper describes a modified, ecologically sound waste treatment technique, where municipal solid waste is anaerobically treated in a lysimeter-scale landfill bioreactor with leachate recirculation to enhance organic degradation. The results demonstrate a substantial decrease in organic matter (BOD 99%, COD 88% and TOC 81%) and a clear decrease in nutrient concentrations especially ammonia (85%) over a period of 1 year with leachate recirculation.

  14. Forecast of biogas generation in Lithuanian regional land fills

    Directory of Open Access Journals (Sweden)

    Brigita Šalčiūnaitė

    2015-10-01

    Full Text Available The amount of generated waste in Lithuania ranges from 35,000 tons to 261,865 tons per year. 35% of this quantity is biodegradable waste – i.e. about 27,830 tons/year. 75% of municipal waste in Lithuania is disposed in landfills. Such management of municipal waste is dangerous because of environmental pollution with the biogas and leachate, increased global greenhouse effect, and so on. From 1 ton of landfill waste it is possible to get about 10 m3 of landfill gas, after using it 13 kWh and 50 kWh of thermal energy could be made. There was presented in this article the estimated amount of biogas produced by Lithuanian regional landfills each separately and all co-production of biogas from landfills potential Lithuania, using the software LandGEM. Total volume of gas liberated in landfills ranges from 7.8 × 106 to 5.8 × 107 m3/year of methane and carbon dioxide in an amount ranging from 3.9 × 106 to 2.9 × 107 m3/year. Minimum quantities of biogas generated in Tauragės regional landfill – 7.8 × 106 m3/year, and the highest – Kaunas regional landfill – 5.8 × 107 m3/year. From the generated biogass it would be possible to yield 2,145 × 108 kWh of electricity and 8.25 × 108 kWh of thermal energy.

  15. Position paper on gas generation in the Waste Isolation Pilot Plant

    Energy Technology Data Exchange (ETDEWEB)

    Brush, L.H.

    1994-11-15

    Gas generation by transuranic (TRU) waste is a significant issue because gas will, if produced in significant quantities, affect the performance of the Waste Isolation Pilot Plant (WIPP) with respect to Environmental Protection Agency (EPA) regulations for the long-term isolation of radioactive and chemically hazardous waste. If significant gas production occurs, it will also affect, and will be affected by, other processes and parameters in WIPP disposal rooms. The processes that will produce gas in WIPP disposal rooms are corrosion, microbial activity and radiolysis. This position paper describes these processes and the models, assumptions and data used to predict gas generation in WIPP disposal rooms.

  16. Sustainable Approach for Landfill Management at Final Processing Site Cikundul in Sukabumi City, Indonesia

    Directory of Open Access Journals (Sweden)

    Sri Darwati

    2012-01-01

    than that of anaerobic landfill. Gas composition at semi aerobic landfill in FPS Sukabumi shows about 6–10% CH4 and about 15–16% O2; for an aerobic landfill, the gas composition is about 47–57% CH4 and about 2–3% O2. In conclusion the concept mining landfill could be developed especially for big cities where it is difficult to find a new site for landfill or to get soil cover for landfill operation. In a sustainable approach, the excavated area can be turned into a new area for landfill cell so that the capacity of existing Final Processing Site can be expanded using the block landfill concept. The landfill should be divided into three blocks: compost block, composting block and active block. Usage of the three blocks are rotated with the intention of using solid waste on the compost block as soil material for the active block through landfill mining.

  17. Comparison between lab- and full-scale applications of in situ aeration of an old landfill and assessment of long-term emission development after completion.

    Science.gov (United States)

    Hrad, Marlies; Gamperling, Oliver; Huber-Humer, Marion

    2013-10-01

    Sustainable landfilling has become a fundamental objective in many modern waste management concepts. In this context, the in situ aeration of landfills has been recognised for its potential to convert conventional anaerobic landfills into biological stabilised state, whereby both current and potential (long-term) emissions of the landfilled waste are mitigated. In recent years, different in situ aeration concepts have been successfully applied in Europe, North America and Asia, all pursuing different objectives and strategies. In Austria, the first full-scale application of in situ landfill aeration by means of low pressure air injection and simultaneous off-gas collection and treatment was implemented on an old, small municipal solid waste (MSW) landfill (2.6ha) in autumn 2007. Complementary laboratory investigations were conducted with waste samples taken from the landfill site in order to provide more information on the transferability of the results from lab- to full-scale aeration measures. In addition, long-term emission development of the stabilised waste after aeration completion was assessed in an ongoing laboratory experiment. Although the initial waste material was described as mostly stable in terms of the biological parameters gas generation potential over 21days (GP21) and respiration activity over 4days (RA4), the lab-scale experiments indicated that aeration, which led to a significant improvement of leachate quality, was accompanied by further measurable changes in the solid waste material under optimised conditions. Even 75weeks after aeration completion the leachate, as well as gaseous emissions from the stabilised waste material, remained low and stayed below the authorised Austrian discharge limits. However, the application of in situ aeration at the investigated landfill is a factor 10 behind the lab-based predictions after 3years of operation, mainly due to technical limitations in the full-scale operation (e.g. high air flow resistivity due

  18. Installed capacity of coal seam gas power generation exceeds 480 MW under SGCC s coverage

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The journalist learned from the "National Gas Security Working Conference" held recently that the coal seam gas power generation has been rapidly developed in recent years.As of July 2009,within the SGCC's business area,the power generation units

  19. Analysis of Turkish High School Chemistry Textbooks and Teacher-Generated Questions about Gas Laws

    Science.gov (United States)

    Nakiboglu, Canan; Yildirir, H.

    2011-01-01

    This study presents the results of an analysis of high school chemistry textbooks and teacher-generated questions about gas laws. The materials that were analyzed consisted of 456 questions about gas laws found in seven grade 10 chemistry textbooks and 264 teacher-generated examination questions prepared by seven chemistry teachers from three…

  20. Gas-temperature-dependent generation of cryoplasma jet under atmospheric pressure

    Science.gov (United States)

    Noma, Yuri; Choi, Jai Hyuk; Tomai, Takaaki; Terashima, Kazuo

    2008-09-01

    Plasma with a gas temperature below room temperature is not yet fully understood although it is expected to be an attractive tool for applications to material processing. In the present work, gas-temperature-dependent generation of a cryoplasma jet was studied. So far, we have generated a helium cryoplasma jet (296-5K) under atmospheric pressure. At gas temperatures below 20K, the helium excimer, He2, was observed clearly from by optical emission spectroscopy.

  1. DESIGN, FABRICATION, AND TESTING OF AN ADVANCED, NON-POLLUTING TURBINE DRIVE GAS GENERATOR

    Energy Technology Data Exchange (ETDEWEB)

    Unknown

    2001-10-30

    The objectives of this report period were to continue the development of the Gas Generator design, to complete the hardware and ancillary hardware fabrication, and commence the Test Preparations for the testing of the non-polluting unique power turbine drive gas generator. Focus during this report period has been on testing the Gas Generator. Because of unacceptable delays encountered in a previously competitively selected test site, CES initiated a re-competition of our testing program and selected an alternate test site. Following that selection, CES used all available resources to make preparations for testing the 10 Mw Gas Generator at the new testing site facilities of NTS at Saugus, CA. A substantial portion of this report period was devoted to Testing Preparations, i.e. test facility development, cold- flow testing, calibration testing, performing igniter ignition testing, and then commencement of the completely assembled Gas Generator Assembly Testing, in process at this writing.

  2. Turkey Run Landfill Emissions Dataset

    Data.gov (United States)

    U.S. Environmental Protection Agency — landfill emissions measurements for the Turkey run landfill in Georgia. This dataset is associated with the following publication: De la Cruz, F., R. Green, G....

  3. Simulating the heat budget for waste as it is placed within a landfill operating in a northern climate.

    Science.gov (United States)

    Megalla, Dina; Van Geel, Paul J; Doyle, James T

    2016-09-01

    A landfill gas to energy (LFGTE) facility in Ste. Sophie, Quebec was instrumented with sensors which measure temperature, oxygen, moisture content, settlement, total earth pressure, electrical conductivity and mounding of leachate. These parameters were monitored during the operating phase of the landfill in order to better understand the biodegradation and waste stabilization processes occurring within a LFGTE facility. Conceptual and numerical models were created to describe the heat transfer processes which occur within five waste lifts placed over a two-year period. A finite element model was created to simulate the temperatures within the waste and estimate the heat budget over a four and a half year period. The calibrated model was able to simulate the temperatures measured to date within the instrumented waste profile at the site. The model was used to evaluate the overall heat budget for the waste profile. The model simulations and heat budget provide a better understanding of the heat transfer processes occurring within the landfill and the relative impact of the various heat source/sink and storage terms. Aerobic biodegradation appears to play an important role in the overall heat budget at this site generating 36% of the total heat generated within the waste profile during the waste placement stages of landfill operations.

  4. Group-specific quantification of methanotrophs in landfill gas-purged laboratory biofilters by tyramide signal amplification-fluorescence in situ hybridization.

    Science.gov (United States)

    Wang, Hong; Einola, Juha; Heinonen, Mirja; Kulomaa, Markku; Rintala, Jukka

    2008-09-01

    The aim of this study was to quantitatively analyse methanotrophs in two laboratory landfill biofilters at different biofilter depths and at temperatures which mimicked the boreal climatic conditions. Both biofilters were dominated by type I methanotrophs. The biofilter depth profiles showed that type I methanotrophs occurred in the upper layer, where relatively high O(2) and low CH(4) concentrations were present, whereas type II methanotrophs were mostly distributed in the zone with high CH(4) and low O(2) concentrations. The number of type I methanotrophic cells declined when the temperature was raised from 15 degrees C to 23 degrees C, but increased when lowered to 5 degrees C. A slight decrease in type II methanotrophs was also observed when the temperature was raised from 15 degrees C to 23 degrees C, whereas cell numbers remained constant when lowered to 5 degrees C. The results indicated that low temperature conditions favored both type I and type II methanotrophs in the biofilters.

  5. Features of the type Ⅲ-like source rock and its generated natural gas

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The mother matter of Ordovician source are mainly sapropelic and generate oil in mature stage, since the high plants did not appear in Ordovician period, which is well known by internal and external scholars. Now we find a kind of Orodovician source rock generating mainly light oil and gas in mature stage during appraising source rocks in the Tarim Basin. The organic matters of this source rock are chiefly constructed by benthic brown algae in organisms (showing as macro algae), and are similar to humic source in hydrocarbon generation. The natural gas generated by this kind of source matters is obviously different from the sapropelic gas.

  6. Methane emissions from a Californian landfill, determined from airborne remote sensing and in situ measurements

    Science.gov (United States)

    Krautwurst, Sven; Gerilowski, Konstantin; Jonsson, Haflidi H.; Thompson, David R.; Kolyer, Richard W.; Iraci, Laura T.; Thorpe, Andrew K.; Horstjann, Markus; Eastwood, Michael; Leifer, Ira; Vigil, Samuel A.; Krings, Thomas; Borchardt, Jakob; Buchwitz, Michael; Fladeland, Matthew M.; Burrows, John P.; Bovensmann, Heinrich

    2017-09-01

    Fugitive emissions from waste disposal sites are important anthropogenic sources of the greenhouse gas methane (CH4). As a result of the growing world population and the recognition of the need to control greenhouse gas emissions, this anthropogenic source of CH4 has received much recent attention. However, the accurate assessment of the CH4 emissions from landfills by modeling and existing measurement techniques is challenging. This is because of inaccurate knowledge of the model parameters and the extent of and limited accessibility to landfill sites. This results in a large uncertainty in our knowledge of the emissions of CH4 from landfills and waste management. In this study, we present results derived from data collected during the research campaign COMEX (CO2 and MEthane eXperiment) in late summer 2014 in the Los Angeles (LA) Basin. One objective of COMEX, which comprised aircraft observations of methane by the remote sensing Methane Airborne MAPper (MAMAP) instrument and a Picarro greenhouse gas in situ analyzer, was the quantitative investigation of CH4 emissions. Enhanced CH4 concentrations or CH4 plumes were detected downwind of landfills by remote sensing aircraft surveys. Subsequent to each remote sensing survey, the detected plume was sampled within the atmospheric boundary layer by in situ measurements of atmospheric parameters such as wind information and dry gas mixing ratios of CH4 and carbon dioxide (CO2) from the same aircraft. This was undertaken to facilitate the independent estimation of the surface fluxes for the validation of the remote sensing estimates. During the COMEX campaign, four landfills in the LA Basin were surveyed. One landfill repeatedly showed a clear emission plume. This landfill, the Olinda Alpha Landfill, was investigated on 4 days during the last week of August and first days of September 2014. Emissions were estimated for all days using a mass balance approach. The derived emissions vary between 11.6 and 17.8 kt CH4 yr-1

  7. Detection and quantification of methane leakage from landfills

    Energy Technology Data Exchange (ETDEWEB)

    Ljungberg, Sven-Aake; Maartensson, Stig-Goeran (Univ. of Gaevle, Gaevle (Sweden)); Meijer, Jan-Erik; Rosqvist, Haakan (NSR AB, Helsingborg (Sweden))

    2009-03-15

    The purpose of this project was to detect gas leakage and to measure and quantify methane emission from landfills using modern remote sensing techniques. In this project, a handheld laser instrument and an IR camera were used. The overall objective was to develop cost-effective methods for detecting and quantifying methane emissions from landfills. There are many methods available for measuring the methane concentration in air, both from close-up and from long distances. Combined with the use of a tracer gas, the methane emission from entire landfills can be measured relatively accurately. A number of methods are used to detect leakage from parts of landfill surfaces, but there are few methods for quantifying leakage from sub-zones. Field measurements with the laser instrument and the IR camera were carried out at seven Swedish landfills and two landfills in France. The investigated surfaces at the Swedish landfills were divided into different zones, such as top surface, slope, crest and toe of slope. The field measurements in France were taken over entire landfills. The methane emission varied between the different landfills in the project, and also between the different landfill zones. The results from repeated field measurements indicated that a landfill with a final cap and a successful gas recovery system produces barely measurable emissions. The weak points at a landfill are generally slopes, including crests and toes of slopes. Where the covering of the waste is inadequate, leakage often occurs at lift joints and in areas where waste protrudes through the cover. Other weak points are deficiencies in the gas recovery system. Leachate systems can lead landfill gas and thereby cause methane leakage. Along with wind velocity and variations in atmospheric pressure, moisture content in the ground is an important factor that affects methane emissions from landfill surfaces. Results from field measurements of the same feature/surface at different points in time and

  8. Micro generation of electricity with gasification gas in a engine generator in dual mode; Microgeracao de eletricidade com gas de gaseificacao num motor gerador dual

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Marcelo Jose da; Souza, Samuel Nelson Melegari de; Souza, Abel Alves de; Ricieri, Reinaldo P. [Universidade Estadual do Oeste do Parana (UNIOESTE), Cascavel, PE (Brazil)], E-mail: marcelo_js07@hotmail.com

    2010-07-01

    Among the alternatives to the increase of world energy demand the use of biomass as energy source is one of the most promising as it contributes to reducing emissions of carbon dioxide in the atmosphere. Gasification is a process technology of biomass energy in a gaseous biofuel. The fuel gas got a low calorific value that can be used in diesel engine in dual mode for power generation in isolated communities. This study aimed to evaluate the reduction in the consumption of oil diesel an engine generator, using gas from gasification of wood. The engine generator brand used, it was a BRANCO, with direct injection power of 10 hp and mated to an electric generator 5,5 kW. The fuel gas was produced in a gasifier type co-current. The engine generator was put on load system from 0.5 kW to 3.5 kW through electric bank of heaters. For the oil diesel savings, the gas was injected mixed with intake air, as the oil diesel was normally injected by the injector of the engine (motor dual). The consumption od diesel was measured diesel by means of a precision scale. It was concluded that the engine converted to dual mode when using the gas for the gasification of wood showed a decrease in diesel consumption by up to 57%. (author)

  9. Landfill Mining of Shredder Residues

    DEFF Research Database (Denmark)

    Hansen, Jette Bjerre; Hyks, Jiri; Shabeer Ahmed, Nassera

    In Denmark, shredder residues (SR) are classified as hazardous waste and until January 2012 the all SR were landfilled. It is estimated that more than 1.8 million tons of SR have been landfilled in mono cells. This paper describes investigations conducted at two Danish landfills. SR were excavated...

  10. DESIGN, FABRICATION, AND TESTING OF AN ADVANCED, NON-POLLUTING TURBINE DRIVE GAS GENERATOR

    Energy Technology Data Exchange (ETDEWEB)

    Unknown

    2002-01-31

    The objective of this report period was to continue the development of the Gas Generator design, fabrication and test of the non-polluting unique power turbine drive Gas Generator. Focus during this past report period has been to continue completion the Gas Generator design, completing the brazing and bonding experiments to determine the best method and materials necessary to fabricate the Gas Generator hardware, continuing to making preparations for fabricating and testing this Gas Generator and commencing with the fabrication of the Gas Generator hardware and ancillary hardware. Designs have been completed sufficiently such that Long Lead Items [LLI] have been ordered and upon arrival will be readied for the fabrication process. The keys to this design are the platelet construction of the injectors that precisely measures/meters the flow of the propellants and water all throughout the steam generating process and the CES patented gas generating cycle. The Igniter Assembly injector platelets fabrication process has been completed and bonded to the Igniter Assembly and final machined. The Igniter Assembly is in final assembly and is being readied for testing in the October 2001 time frame. Test Plan dated August 2001, was revised and finalized, replacing Test Plan dated May 2001.

  11. DESIGN, FABRICATION, AND TESTING OF AN ADVANCED, NON-POLLUTING TURBINE DRIVE GAS GENERATOR

    Energy Technology Data Exchange (ETDEWEB)

    Unknown

    2002-01-31

    The objective of this report period was to continue the development of the Gas Generator design, fabrication and test of the non-polluting unique power turbine drive Gas Generator. Focus during this past report period has been to continue completion the Gas Generator design, completing the brazing and bonding experiments to determine the best method and materials necessary to fabricate the Gas Generator hardware, continuing to making preparations for fabricating and testing this Gas Generator and commencing with the fabrication of the Gas Generator hardware and ancillary hardware. Designs have been completed sufficiently such that Long Lead Items [LLI] have been ordered and upon arrival will be readied for the fabrication process. The keys to this design are the platelet construction of the injectors that precisely measures/meters the flow of the propellants and water all throughout the steam generating process and the CES patented gas generating cycle. The Igniter Assembly injector platelets fabrication process has been completed and bonded to the Igniter Assembly and final machined. The Igniter Assembly is in final assembly and is being readied for testing in the October 2001 time frame. Test Plan dated August 2001, was revised and finalized, replacing Test Plan dated May 2001.

  12. Fuel prices, emission standards, and generation costs for coal vs natural gas power plants.

    Science.gov (United States)

    Pratson, Lincoln F; Haerer, Drew; Patiño-Echeverri, Dalia

    2013-05-07

    Low natural gas prices and stricter, federal emission regulations are promoting a shift away from coal power plants and toward natural gas plants as the lowest-cost means of generating electricity in the United States. By estimating the cost of electricity generation (COE) for 304 coal and 358 natural gas plants, we show that the economic viability of 9% of current coal capacity is challenged by low natural gas prices, while another 56% would be challenged by the stricter emission regulations. Under the current regulations, coal plants would again become the dominant least-cost generation option should the ratio of average natural gas to coal prices (NG2CP) rise to 1.8 (it was 1.42 in February 2012). If the more stringent emission standards are enforced, however, natural gas plants would remain cost competitive with a majority of coal plants for NG2CPs up to 4.3.

  13. Proposed Expansion of Acme Landfill Operations.

    Science.gov (United States)

    1982-08-01

    decays, it produces bacteria that release gases. Methane develops in phases. Initially, during a phase which can last several days to months, a...90 and 95°F. Another factor which affects landfill gas production is pH. Methanogenic bacteria need a pH near 7.0 to produce optimal amounts of...Los Osos-Millsholm-Los Gatos soil association while the other four sites were located in the Altamont-Diablo-Fontana association. A standard slope

  14. Numerical solution of moving boundary problem for deposition process in solid fuel gas generator

    Science.gov (United States)

    Volokhov, V. M.; Dorofeenko, S. O.; Sharov, M. S.; Toktaliev, P. D.

    2016-11-01

    Moving boundary problem in application to process of depositions formation in gas generator are considered. Gas generator, as a part of fuel preparation system of high-speed vehicle, convert solid fuel into multicomponent multiphase mixture, which further burned down in combustion chamber. Mathematical model of two-phase “gas-solid particles” flow, including Navier-Stokes equations for turbulent flow in gas generator and mass, impulse conservations laws for elementary depositions layer are proposed. Verification of proposed mathematical model for depositions mass in gas generator conditions is done. Further possible improvements of proposed model, based on more detail accounting of particle-wall interaction and wall's surface adhesion properties are analyzed.

  15. Test Gas Generation from Pure Liquids: An Application-Oriented Overview of Methods in a Nutshell

    Directory of Open Access Journals (Sweden)

    Yue Li

    2012-01-01

    Full Text Available The generation of test gas from pure liquids has a wide variety of applications in laboratory and field experiments, for which the quality of the test gas is of significance. Therefore, various methods for test gas generation have been designed. Each method has unique advantages and disadvantages. Thus, a short overview is presented within the scope of this paper. Furthermore, a common bubbler system is presented, which was built to generate test gas from volatile organic compounds for experimental usage in laboratory applications. An analysis is conducted with respect to the generated concentrations at different temperatures and flow rates of the diluting gas. Accuracy and stability of this method are investigated.

  16. Carbon and hydrogen isotopic composition and generation pathway of biogenic gas in China

    Institute of Scientific and Technical Information of China (English)

    SHEN Ping; WANG Xiaofeng; XU Yin; SHI Baoguang; XU Yongchang

    2009-01-01

    The carbon and hydrogen isotopic composition of biogenic gas is of great importance for the study of its generation pathway and reservoiring characteristics. In this paper, the formation pathways and reservoiring characteristics of biogenic gas reservoirs in China are described in terms of the carbon and hydrogen isotopic compositions of 31 gas samples from 10 biogenic gas reservoirs. The study shows that the hydrogen isotopic compositions of these biogenic gas reservoirs can be divided into three intervals:δDCH4>-200‰,-250‰<δDCH4<-200‰ and δDCH4<-250‰. The forerunners believed that the main generation pathway of biogenic gas under the condition of continental fresh water is acetic fermentation. Our research results showed that the generation pathway of biogenic gas under the condition of marine facies is typical CO2- reduction, the biogenic gas has heavy hydrogen isotopic composition: its δDCH4 values are higher than -200‰; that the biogenic gas under the condition of continental facies also was generated by the same way, but its hydrogen isotopic composition is lighter than that of biogenetic gas generated under typical marine facies condition: -250‰<δDCH4<-200‰, the δDCH4 values may be related to the salinity of the water medium in ancient lakes. From the relevant data of the Qaidam Basin, it can be seen that the hydrogen isotopic composition of biogenic methane has the same variation trend with increasing salinity of water medium. There are biogenic gas reservoirs formed in transitional regions under the condition of continental facies. These gas reservoirs resulted from both CO2- reduction and acetic fermentation, the formation of which may be related to the non-variant salinity of ancient water medium and the relatively high geothermal gradient, as is the case encountered in the Baoshan Basin. The biogenic gas generating in these regions has light hydrogen isotopic composition: δDCH4<-250‰, and relatively heavy carbon isotopic

  17. Landfills as critical infrastructures: analysis of observational datasets after 12 years of non-invasive monitoring

    Science.gov (United States)

    Scozzari, Andrea; Raco, Brunella; Battaglini, Raffaele

    2016-04-01

    This work presents the results of more than ten years of observations, performed on a regular basis, on a municipal solid waste disposal located in Italy. Observational data are generated by the combination of non-invasive techniques, involving the direct measurement of biogas release to the atmosphere and thermal infrared imaging. In fact, part of the generated biogas tends to escape from the landfill surface even when collecting systems are installed and properly working. Thus, methodologies for estimating the behaviour of a landfill system by means of direct and/or indirect measurement systems have been developed in the last decades. It is nowadays known that these infrastructures produce more than 20% of the total anthropogenic methane released to the atmosphere, justifying the need for a systematic and efficient monitoring of such infrastructures. During the last 12 years, observational data regarding a solid waste disposal site located in Tuscany (Italy) have been collected on a regular basis. The collected datasets consist in direct measurements of gas flux with the accumulation chamber method, combined with the detection of thermal anomalies by infrared radiometry. This work discusses the evolution of the estimated performance of the landfill system, its trends, the benefits and the critical aspects of such relatively long-term monitoring activity.

  18. System dynamics of the competition of municipal solid waste to landfill, electricity, and liquid fuel in California

    Energy Technology Data Exchange (ETDEWEB)

    Westbrook, Jessica; Malczynski, Leonard A.; Manley, Dawn Kataoka

    2014-03-01

    A quantitative system dynamics model was created to evaluate the economic and environmental tradeoffs between biomass to electricity and to liquid fuel using MSW biomass in the state of California as a case study. From an environmental perspective, landfilling represents the worst use of MSW over time, generating more greenhouse gas (GHG) emissions compared to converting MSW to liquid fuel or to electricity. MSW to ethanol results in the greatest displacement of GHG emissions per dollar spent compared to MSW to electricity. MSW to ethanol could save the state of California approximately $60 billion in energy costs by 2050 compared to landfilling, while also reducing GHG emissions state-wide by approximately 140 million metric tons during that timeframe. MSW conversion to electricity creates a significant cost within the state's electricity sector, although some conversion technologies are cost competitive with existing renewable generation.

  19. Field assessment of semi-aerobic condition and the methane correction factor for the semi-aerobic landfills provided by IPCC guidelines.

    Science.gov (United States)

    Jeong, Sangjae; Nam, Anwoo; Yi, Seung-Muk; Kim, Jae Young

    2015-02-01

    According to IPCC guidelines, a semi-aerobic landfill site produces one-half of the amount of CH4 produced by an equally-sized anaerobic landfill site. Therefore categorizing the landfill type is important on greenhouse gas inventories. In order to assess semi-aerobic condition in the sites and the MCF value for semi-aerobic landfill, landfill gas has been measured from vent pipes in five semi-aerobically designed landfills in South Korea. All of the five sites satisfied requirements of semi-aerobic landfills in 2006 IPCC guidelines. However, the ends of leachate collection pipes which are main entrance of air in the semi-aerobic landfill were closed in all five sites. The CH4/CO2 ratio in landfill gas, indicator of aerobic and anaerobic decomposition, ranged from 1.08 to 1.46 which is higher than the values (0.3-1.0) reported for semi-aerobic landfill sites and is rather close to those (1.0-2.0) for anaerobic landfill sites. The low CH4+CO2% in landfill gas implied air intrusion into the landfill. However, there was no evidence that air intrusion has caused by semi-aerobic design and operation. Therefore, the landfills investigated in this study are difficult to be classified as semi-aerobic landfills. Also MCF of 0.5 may significantly underestimate methane emissions compared to other researches. According to the carbon mass balance analyses, the higher MCF needs to be proposed for semi-aerobic landfills. Consequently, methane emission estimate should be based on field evaluation for the semi-aerobically designed landfills. Copyright © 2015. Published by Elsevier Ltd.

  20. Aeration of the teuftal landfill: Field scale concept and lab scale simulation.

    Science.gov (United States)

    Ritzkowski, Marco; Walker, Beat; Kuchta, Kerstin; Raga, Roberto; Stegmann, Rainer

    2016-09-01

    Long lasting post-closure care (PCC) is often the major financial burden for operators of municipal solid waste (MSW) landfills. Beside costs for the installation and maintenance of technical equipment and barriers, in particular long term treatment of leachate and landfill gas has to be paid from capital surplus. Estimations based on laboratory experiments project time periods of many decades until leachate quality allows for direct discharge (i.e. no need for further purification). Projections based on leachate samples derived from the last 37years for 35 German landfills confirm these assumption. Moreover, the data illustrate that in particular ammonium nitrogen concentrations are likely to fall below limit values only after a period of 300years. In order to avoid long lasting PCC the operator of Teuftal landfill, located in the Swiss canton Bern, decided to biologically stabilize the landfill by means of a combined in situ aeration and moisturization approach. In December 2014 the aeration started at a landfill section containing approximately 30% of the total landfill volume. From summer 2016 onwards the remaining part of the landfill will be aerated. Landfill aeration through horizontal gas and leachate drains is carried out for the first time in field scale in Europe. The technical concept is described in the paper. Parallel to field scale aeration, investigations for the carbon and nitrogen turnover are carried out by means of both simulated aerated landfills and simulated anaerobic landfills. The results presented in this paper demonstrate that aeration is capable to enhance, both carbon mobilization and discharge via the gas phase. This effect comes along with a significant increase in bio-stabilization of the waste organic fraction, which positively affects the landfill emission behavior in the long run. In terms of leachate pollution reduction it could be demonstrated that the organic load decrease fast and widely independent of the adjusted aeration

  1. Hourly weather forecasts for gas turbine power generation

    OpenAIRE

    G. Giunta; R. Vernazza; Salerno, R.; Ceppi, A.; Ercolani, G.; Mancini, M

    2017-01-01

    An hourly short-term weather forecast can optimize processes in Combined Cycle Gas Turbine (CCGT) plants by helping to reduce imbalance charges on the national power grid. Consequently, a reliable meteorological prediction for a given power plant is crucial for obtaining competitive prices for the electric market, better planning and stock management, sales and supplies of energy sources. The paper discusses the short-term hourly temperature forecasts, at lead time day+1 and day+2, over a per...

  2. Analysis of the contaminants released from municipal solid waste landfill site: A case study.

    Science.gov (United States)

    Samadder, S R; Prabhakar, R; Khan, D; Kishan, D; Chauhan, M S

    2017-02-15

    Release and transport of leachate from municipal solid waste landfills pose a potential hazard to both surrounding ecosystems and human populations. In the present study, soil, groundwater, and surface water samples were collected from the periphery of a municipal solid waste landfill (located at Ranital of Jabalpur, Madhya Pradesh, India) for laboratory analysis to understand the release of contaminants. The landfill does not receive any solid wastes for dumping now as the same is under a landfill closure plan. Groundwater and soil samples were collected from the bore holes of 15m deep drilled along the periphery of the landfill and the surface water samples were collected from the existing surface water courses near the landfill. The landfill had neither any bottom liner nor any leachate collection and treatment system. Thus the leachate generated from the landfills finds paths into the groundwater and surrounding surface water courses. Concentrations of various physico-chemical parameters including some toxic metals (in collected groundwater, soil, and surface water samples) and microbiological parameters (in surface water samples) were determined. The analyzed data were integrated into ArcGIS environment and the spatial distribution of the metals and other physic- chemical parameter across the landfill was extrapolated to observe the distribution. The statistical analysis and spatial variations indicated the leaching of metals from the landfill to the groundwater aquifer system. The study will help the readers and the municipal engineers to understand the release of contaminants from landfills for better management of municipal solid wastes.

  3. Effects of Globally Waste Disturbing Activities on Gas Generation, Retention, and Release in Hanford Waste Tanks

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, Charles W.; Fountain, Matthew S.; Huckaby, James L.; Mahoney, Lenna A.; Meyer, Perry A.; Wells, Beric E.

    2005-08-02

    Various operations are authorized in Hanford single- and double-shell tanks that disturb all or a large fraction of the waste. These globally waste-disturbing activities have the potential to release a large fraction of the retained flammable gas and to affect future gas generation, retention, and release behavior. This report presents analyses of the expected flammable gas release mechanisms and the potential release rates and volumes resulting from these activities. The background of the flammable gas safety issue at Hanford is summarized, as is the current understanding of gas generation, retention, and release phenomena. Considerations for gas monitoring and assessment of the potential for changes in tank classification and steady-state flammability are given.

  4. Gas Foil Bearings for Space Propulsion Nuclear Electric Power Generation

    Science.gov (United States)

    Howard, Samuel A.; DellaCorte, Christopher

    2006-01-01

    The choice of power conversion technology is critical in directing the design of a space vehicle for the future NASA mission to Mars. One candidate design consists of a foil bearing supported turbo alternator driven by a helium-xenon gas mixture heated by a nuclear reactor. The system is a closed-loop, meaning there is a constant volume of process fluid that is sealed from the environment. Therefore, foil bearings are proposed due to their ability to use the process gas as a lubricant. As such, the rotor dynamics of a foil bearing supported rotor is an important factor in the eventual design. The current work describes a rotor dynamic analysis to assess the viability of such a system. A brief technology background, assumptions, analyses, and conclusions are discussed in this report. The results indicate that a foil bearing supported turbo alternator is possible, although more work will be needed to gain knowledge about foil bearing behavior in helium-xenon gas.

  5. Sanitary landfills. (Latest citations from the EI Compendex*plus database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-04-01

    This bibliography contains citations concerning refuse disposal in sanitary landfills. Among the topics reviewed are site selection criteria, leachate analysis and treatment, and economic and management aspects. Hydrologic studies pertaining to contaminant transport, and the use of liners and covers are discussed. Considerable attention is given to gas generation and recovery, and specific operations are described. Citations pertaining specifically to hazardous and industrial waste materials are excluded. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  6. Accounting for fuel price risk: Using forward natural gas prices instead of gas price forecasts to compare renewable to natural gas-fired generation

    Energy Technology Data Exchange (ETDEWEB)

    Bolinger, Mark; Wiser, Ryan; Golove, William

    2003-08-13

    Against the backdrop of increasingly volatile natural gas prices, renewable energy resources, which by their nature are immune to natural gas fuel price risk, provide a real economic benefit. Unlike many contracts for natural gas-fired generation, renewable generation is typically sold under fixed-price contracts. Assuming that electricity consumers value long-term price stability, a utility or other retail electricity supplier that is looking to expand its resource portfolio (or a policymaker interested in evaluating different resource options) should therefore compare the cost of fixed-price renewable generation to the hedged or guaranteed cost of new natural gas-fired generation, rather than to projected costs based on uncertain gas price forecasts. To do otherwise would be to compare apples to oranges: by their nature, renewable resources carry no natural gas fuel price risk, and if the market values that attribute, then the most appropriate comparison is to the hedged cost of natural gas-fired generation. Nonetheless, utilities and others often compare the costs of renewable to gas-fired generation using as their fuel price input long-term gas price forecasts that are inherently uncertain, rather than long-term natural gas forward prices that can actually be locked in. This practice raises the critical question of how these two price streams compare. If they are similar, then one might conclude that forecast-based modeling and planning exercises are in fact approximating an apples-to-apples comparison, and no further consideration is necessary. If, however, natural gas forward prices systematically differ from price forecasts, then the use of such forecasts in planning and modeling exercises will yield results that are biased in favor of either renewable (if forwards < forecasts) or natural gas-fired generation (if forwards > forecasts). In this report we compare the cost of hedging natural gas price risk through traditional gas-based hedging instruments (e

  7. The generation and its sealing condition of natural gas in the Tadong area

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Focusing on the two natural gas exploration geological problems with abundant source of oil cracking gas in the late stage and the sealing condition of the oil cracking gas reservoir,the kinetics of oil cracking gas and the evaluation parameters of gas cap rock are adopted to the study on the natural gas accumulation conditions in the Tadong area. Both the study on the kinetics of oil cracking gas and the statistical results of reservoir bitumen reveal that the geological formation of oil cracking gas in the Tadong area is located in the top of Cambrian. Two kinds of oil cracking gas geological models at least,namely well Mandong-1’s early rapid generation model(Middle Ordovician-end Silurian) and peak cracking model(with the natural gas conversion rate >90%) ,namely well Yingnan-2’s two-stage generation model of oil cracking gas,have been set up. The oil cracking gas of Yingnan-2 in the late stage is very significant in the evaluation of natural gas exploration in the Tadong area. The evaluation results of the cap rock show that the microscopic parameters of cap rock from the lower assemblage of Cambrian-Ordovician are better than those from the upper assemblage. The former has strong capillary sealing ability and higher cap rock breakthrough pressure than the upper assemblage,with strong sealing ability,so that natural gas dissipates mainly by diffusion. According to the above investigations,the lower assemblage Cambrian-Ordovician natural gas of Kongquehe slope,Tadong low uplift and Yingjisu depression in the Tadong area prospects well.

  8. Relative Role of Gas Generation and Displacement Rates in Cavity Nucleation and Growth

    DEFF Research Database (Denmark)

    Singh, Bachu Narain; Foreman, A. J E.

    1984-01-01

    Problems of helium diffusion and clustering during irradiation are analysed. Using the “homogeneous” nucleation theory , the effect of damage rate on cavity density is calculated for different gas generation to damage rate ratios. The influence of gas mobility on cavity nucleation has been evalua...

  9. Transition metal catalysis in the generation of petroleum and natural gas. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Mango, F.D.

    1997-01-21

    This project originated on the premise that natural gas could be formed catalytically in the earth rather than thermally as commonly believed. The intention was to test this hypothetical view and to explore generally the role of sedimentary metals in the generation of light hydrocarbons (C1 - C9). We showed the metalliferous source rocks are indeed catalytic in the generation of natural gas. Various metal compounds in the pure state show the same levels of catalytic activity as sedimentary rocks and the products are identical. Nickel is particularly active among the early transition metals and is projected to remain catalytically robust at all stages of catagenesis. Nickel oxide promotes the formation of n-alkanes in addition to natural gas (NG), demonstrating the full scope of the hypothetical catalytic process: The composition of catalytic gas duplicates the entire range of natural gas, from so-called wet gas to dry gas (60 to 95+ wt % methane), while gas generated thermally is consistently depleted in methane (10 to 60 wt % methane). These results support the view that metal catalysis is a major pathway through which natural gas is formed in the earth.

  10. Hourly weather forecasts for gas turbine power generation

    Directory of Open Access Journals (Sweden)

    G. Giunta

    2017-06-01

    Full Text Available An hourly short-term weather forecast can optimize processes in Combined Cycle Gas Turbine (CCGT plants by helping to reduce imbalance charges on the national power grid. Consequently, a reliable meteorological prediction for a given power plant is crucial for obtaining competitive prices for the electric market, better planning and stock management, sales and supplies of energy sources. The paper discusses the short-term hourly temperature forecasts, at lead time day+1 and day+2, over a period of thirteen months in 2012 and 2013 for six Italian CCGT power plants of 390 MW each (260 MW from the gas turbine and 130 MW from the steam turbine. These CCGT plants are placed in three different Italian climate areas: the Po Valley, the Adriatic coast, and the North Tyrrhenian coast. The meteorological model applied in this study is the eni-Kassandra Meteo Forecast (e‑kmf™, a multi-model approach system to provide probabilistic forecasts with a Kalman filter used to improve accuracy of local temperature predictions. Performance skill scores, computed by the output data of the meteorological model, are compared with local observations, and used to evaluate forecast reliability. In the study, the approach has shown good overall scores encompassing more than 50,000 hourly temperature values. Some differences from one site to another, due to local meteorological phenomena, can affect the short-term forecast performance, with consequent impacts on gas-to-power production and related negative imbalances. For operational application of the methodology in CCGT power plant, the benefits and limits have been successfully identified.

  11. Potential for the energetic use of waste gas in Flanders; Potentieel voor het energetisch gebruik van stortgassen in Vlaanderen

    Energy Technology Data Exchange (ETDEWEB)

    De Spiegeleer, E. [Vlaamse Instelling voor Technologisch Onderzoek, Mol (Belgium)

    1999-03-01

    The department of Natural Resources and Energy of the Ministry of the Flemish Community wanted to know the stand of affairs of the use of waste gas on the Flemish landfills in 1998. On the basis of a multi-phase model for waste gas production (according Dutch model) and data provided by the operators, the waste gas potential could be calculated for each landfill. The total waste gas production in Flanders is estimated at 75 million m3 in 1999. This brings the extracting amount of waste gas at 60 million m3 (in optimal circumstances, extracting efficiency 80%). Because the activities will continue for some years on categorie2 landfills, the waste gas production will increase. But the global waste gas potential will decrease as an effect of the evolution in the composition (less organic material) and the amount of waste that will be dumped, plus the landfills will be closed gradually. The possible savings of primary energy and the reduced CO2-emissions by the energetic apply of the global waste potential in Flanders is being estimated at about 695.000 GJ or 63.000 ton CO2. The generation of electricity with the help of a gas engine-generator unit is from technical and economical point of view the most achievable option for the operators. The price of the delivered energy is decisive for the cost-effectiveness of concrete investment projects. Only subsidies of the government makes the pay-back time for waste gas projects acceptable.

  12. Conical flow near singular rays. [shock generation in ideal gas

    Science.gov (United States)

    Zahalak, G. I.; Myers, M. K.

    1974-01-01

    The steady flow of an ideal gas past a conical body is investigated by the method of matched asymptotic expansions, with particular emphasis on the flow near the singular ray occurring in linearized theory. The first-order problem governing the flow in this region is formulated, leading to the equation of Kuo, and an approximate solution is obtained in the case of compressive flow behind the main front. This solution is compared with the results of previous investigations with a view to assessing the applicability of the Lighthill-Whitham theories.

  13. The impact of municipal solid waste landfills in Suceava County on air quality

    Directory of Open Access Journals (Sweden)

    Dumitru MIHĂILĂ

    2014-08-01

    Full Text Available The location of municipal solid waste (MSW landfills in inappropriate places is a serious risk to the quality of all environmental factors. These waste disposal sites can become major sources of air quality deterioration through emissions of toxic gas resulted from anaerobic decomposition of organic waste. The paper discusses in detail the qualitative and quantitative effects of municipal waste landfills of the main urban settlements in Suceava County (Suceava City municipal landfill and Gura Humorului, Rădăuţi, Siret, Câmpulung Moldovenesc, Fălticeni and Vatra Dornei urban waste landfills on air quality. The dispersion of methane emitted from the largest MSW landfill in the county, the Suceava municipal landfill respectively, is also presented, taking into account seasonal, daytime and nighttime meteorological parameters

  14. Evaluation of simultaneous biodegradation of methane and toluene in landfill covers.

    Science.gov (United States)

    Su, Yao; Zhang, Xuan; Wei, Xiao-Meng; Kong, Jiao-Yan; Xia, Fang-Fang; Li, Wei; He, Ruo

    2014-06-15

    The biodegradation of CH4 and toluene in landfill cover soil (LCS) and waste biocover soil (WBS) was investigated with a serial toluene concentration in the headspace of landfill cover microcosms in this study. Compared with the LCS sample, the higher CH4 oxidation activity and toluene-degrading capacity occurred in the WBS sample. The co-existence of toluene in landfill gas would positively or negatively affect CH4 oxidation, mainly depending on the toluene concentrations and exposure time. The nearly complete inhibition of toluene on CH4 oxidation was observed in the WBS sample at the toluene concentration of ∼ 80,000 mg m(-3), which was about 10 times higher than that in the LCS sample. The toluene degradation rates in both landfill covers fitted well with the Michaelis-Menten model. These findings showed that WBS was a good alternative landfill cover material to simultaneously mitigate emissions of CH4 and toluene from landfills to the atmosphere.

  15. Modeling of microbial gas generation: application to the eastern Mediterranean “Biogenic Play”

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, M.; Dubille, M.; Montadert, L.

    2016-07-01

    Biogenic gas is becoming increasingly important as an exploration target in the petroleum industry because it occurs in geologically predictable circumstances and in large quantities at shallow depths as free gas or gas hydrates. As accumulations of biogenic gas result in a subtle synchronization between early generation and early trapping, we integrated a macroscopic model of microbial gas generation within a 3D basin and petroleum system forward simulator. The macroscopic model is based on a microscopic model, which consists in a 1D sedimentary column that accounts for sedimentation, compaction, Darcy flow and Diffusion flow. The organic carbon is the only non-soluble element considered in this version of the model. The dissolved elements are O2, SO4 2-, H2, CH3COOH, and CH4. Methane is dissolved in water or present as a free phase if its concentration exceeds its solubility at given pressure and temperature. In this microscopic model, the transformation of substrate into biomass is described through a set of logistic equations coupled with the transport equations (advection and diffusion). Based on the microscopic considerations we developed the macroscopic model of low maturity/biogenic gas generation in which hydrocarbons are generated through first order kinetic reactions at low maturity. This macroscopic model is adapted to petroleum system modeling at basin scale with TemisFlow®, which aims to understand and predict hydrocarbon generation, migration, and accumulation. It is composed of: i) A source rock criteria which allow defining the biogenic gas source rocks potential and ii) A kinetic model of methane generation. The previous model has been successfully applied on different basins such as the Carupano Basin from the offshore Venezuela, the Magdalena Delta (offshore Colombia) and the offshore Vietnam where direct observations of low-maturity gas were available. Furthermore, it has been applied in the offshore Lebanon in order to check the viability of

  16. N 2O emissions at municipal solid waste landfill sites: Effects of CH 4 emissions and cover soil

    Science.gov (United States)

    Zhang, Houhu; He, Pinjing; Shao, Liming

    Municipal solid waste landfills are the significant anthropogenic sources of N 2O due to the cooxidation of ammonia by methane-oxidizing bacteria in cover soils. Such bacteria could be developed through CH 4 fumigation, as evidenced by both laboratory incubation and field measurement. During a 10-day incubation with leachate addition, the average N 2O fluxes in the soil samples, collected from the three selected landfill covers, were multiplied by 1.75 ( p landfill sites, N 2O fluxes in two landfill sites were significantly correlated with the variations of the CH 4 emissions without landfill gas recovery ( p landfill gas recovery in another landfill site ( p > 0.05). The annual average N 2O flux was 176 ± 566 μg N 2O-N m -2 h -1 ( p landfill site, which was 72% ( p landfill sites, respectively. The magnitude order of N 2O emissions in three landfill sites was also coincident by the results of laboratory incubation, suggesting the sandy soil cover could mitigate landfill N 2O emissions.

  17. FABRICATE AND TEST AN ADVANCED NON-POLLUTING TURBINE DRIVE GAS GENERATOR

    Energy Technology Data Exchange (ETDEWEB)

    Eugene Baxter; Roger E. Anderson; Stephen E. Doyle

    2003-06-01

    In September 2000 the Department of Energy's National Energy Technology Laboratory (DOE/NETL) contracted with Clean Energy Systems, Inc. (CES) of Sacramento, California to design, fabricate, and test a 20 MW{sub t} (10 MW{sub e}) gas generator. Program goals were to demonstrate a non-polluting gas generator at temperatures up to 3000 F at 1500 psi, and to demonstrate resulting drive gas composition, comprising steam and carbon dioxide substantially free of pollutants. Following hardware design and fabrication, testing, originally planned to begin in the summer of 2001, was delayed by unavailability of the contracted test facility. CES designed, fabricated, and tested the proposed gas generator as originally agreed. The CES process for producing near-zero-emissions power from fossil fuels is based on the near-stoichiometric combustion of a clean gaseous fuel with oxygen in the presence of recycled water, to produce a high-temperature, high-pressure turbine drive fluid comprising steam and carbon dioxide. Tests demonstrated igniter operation over the prescribed ranges of pressure and mixture ratios. Ignition was repeatable and reliable through more than 100 ignitions. Injector design ''A'' was operated successfully at both low power ({approx}20% of rated power) and at rated power ({approx}20 MW{sub t}) in more than 95 tests. The uncooled gas generator configuration (no diluent injectors or cooldown chambers installed) produced drive gases at temperatures approaching 3000 F and at pressures greater than 1550 psia. The fully cooled gas generator configuration, with cooldown chambers and injector ''A'', operated consistently at pressures from 1100 to 1540 psia and produced high pressure, steam-rich turbine drive gases at temperatures ranging from {approx}3000 to as low as 600 F. This report includes description of the intended next steps in the gas generator technology demonstration and traces the anticipated pathway to

  18. FABRICATE AND TEST AN ADVANCED NON-POLLUTING TURBINE DRIVE GAS GENERATOR

    Energy Technology Data Exchange (ETDEWEB)

    Eugene Baxter; Roger E. Anderson; Stephen E. Doyle

    2003-06-01

    In September 2000 the Department of Energy's National Energy Technology Laboratory (DOE/NETL) contracted with Clean Energy Systems, Inc. (CES) of Sacramento, California to design, fabricate, and test a 20 MW{sub t} (10 MW{sub e}) gas generator. Program goals were to demonstrate a non-polluting gas generator at temperatures up to 3000 F at 1500 psi, and to demonstrate resulting drive gas composition, comprising steam and carbon dioxide substantially free of pollutants. Following hardware design and fabrication, testing, originally planned to begin in the summer of 2001, was delayed by unavailability of the contracted test facility. CES designed, fabricated, and tested the proposed gas generator as originally agreed. The CES process for producing near-zero-emissions power from fossil fuels is based on the near-stoichiometric combustion of a clean gaseous fuel with oxygen in the presence of recycled water, to produce a high-temperature, high-pressure turbine drive fluid comprising steam and carbon dioxide. Tests demonstrated igniter operation over the prescribed ranges of pressure and mixture ratios. Ignition was repeatable and reliable through more than 100 ignitions. Injector design ''A'' was operated successfully at both low power ({approx}20% of rated power) and at rated power ({approx}20 MW{sub t}) in more than 95 tests. The uncooled gas generator configuration (no diluent injectors or cooldown chambers installed) produced drive gases at temperatures approaching 3000 F and at pressures greater than 1550 psia. The fully cooled gas generator configuration, with cooldown chambers and injector ''A'', operated consistently at pressures from 1100 to 1540 psia and produced high pressure, steam-rich turbine drive gases at temperatures ranging from {approx}3000 to as low as 600 F. This report includes description of the intended next steps in the gas generator technology demonstration and traces the anticipated pathway to

  19. Performance appraisal of gas based electric power generation system using transfer function modelling

    Directory of Open Access Journals (Sweden)

    Chidozie Chukwuemeka Nwobi-Okoye

    2015-06-01

    Full Text Available Gas flaring for years has been a major environmental problem in many parts of the world. One way of solving the problem of gas flaring is to effectively utilize the abundant supply of gas for power generation. To effectively utilize gas for power generation requires highly efficient gas turbines and power facilities. Traditional methods of assessing the efficiency of power generation turbines do not take into consideration the stochastic nature of gas input and power output. This is because in a power generation system, as in any typical production system, there is generally marked variability in both input (gas and output (power of the process. This makes the determination of the relationship between input and output quite complex. This work utilized Box-Jenkins transfer function modelling technique, an integral part of statistical principle of time series analysis to model the efficiency of a gas power plant. This improved way of determining the efficiency of gas power generation facilities involves taking input–output data from a gas power generation process over a 10-year period and developing transfer function models of the process for the ten years, which are used as performance indicators. Based on the performance indicators obtained from the models, the results show that the efficiency of the gas power generation facility was best in the years 2007–2011 with a coefficient of performance of 0.002343345. Similarly, with a coefficient of performance of 0.002073617, plant performance/efficiency was worst in the years 2002–2006. Using the traditional method of calculating efficiency the values of 0.2613 and 0.2516 were obtained for years 2002–2006 and 2007–2011 respectively. The result is remarkable because given the state of the facilities, it correctly predicted the period of expected high system performance i.e. 2002–2006 period, but the traditional efficiency measurement method failed to do so. Ordinarily, using efficiency

  20. Comparison between controlled landfill reactor and conditioned landfill bioreactor

    Institute of Scientific and Technical Information of China (English)

    LUO Feng; CHEN Wan-zhi; SONG Fu-zhong; LI Xiao-peng; ZHANG Guo-qing

    2004-01-01

    Bioreactor landfills allow a more active landfill management that recognizes the biological, chemical and physical processes involved in a landfill environment. The results of laboratory-scale simulators of landfill reactors treating municipal solid wastes were studied, the effect of solid waste size, leachate recirculation, nutrient balance, pH value, moisture content and temperature on the rate of municipal solid waste(MSW) biodegradation were determined, and it indicated the optimum pH value, moisture content and temperature can used to decompose MSW. The results of waste biodegradation were compared with that of the simulators of the leachate-recirculated landfill and conservative sanitary landfill. In the control experiment the antitheses of a decreasing trend of the organic load, measured as biological oxygen demand and chemical oxygen demand, was shown, and heavy metals concentration was observed. An obvious enhancement of effective disposal from simulator of conservative sanitary landfill(CSL), to that of leachate-recirculated landfill(LRL) and to that of conditioned bioreactor landfill(CBL) would be noted, through displaying the compared results of solid waste settlement, heavy metal concentration in leachate, methane production rate, biogas composition, BOD and COD as well as their ratio.

  1. Magnetic Field Generation and Zonal Flows in the Gas Giants

    Science.gov (United States)

    Duarte, L.; Wicht, J.; Gastine, T.

    2013-12-01

    The surface dynamics of Jupiter and Saturn is dominated by a banded system of fierce zonal winds. The depth of these winds remains unclear but they are thought to be confined to the very outer envelopes where hydrogen remains molecular and the electrical conductivity is negligible. The dynamo responsible for the dipole dominated magnetic fields of both Gas Giants, on the other hand, likely operates in the deeper interior where hydrogen assumes a metallic state. We present numerical simulations that attempt to model both the zonal winds and the interior dynamo action in an integrated approach. Using the anelastic version of the MHD code MagIC, we explore the effects of density stratification and radial electrical conductivity variations. The electrical conductivity is assumed to remain constant in the thicker inner metallic region and decays exponentially towards the outer boundary throughout the molecular envelope. Our results show that the combination of stronger density stratification (Δρ≈55) and a weaker conducting outer layer is essential for reconciling dipole dominated dynamo action and a fierce equatorial zonal jet. Previous simulations with homogeneous electrical conductivity show that both are mutually exclusive, with solutions either having strong zonal winds and multipolar magnetic fields or weak zonal winds and dipole dominated magnetic fields. The particular setup explored here allows the equatorial jet to remain confined to the weaker conducting region where is does not interfere with the deeper seated dynamo action. The equatorial jet can afford to remain geostrophic and reaches throughout the whole shell. This is not an option for the additional mid to higher latitude jets, however. In dipole dominated dynamo solutions, appropriate for the Gas Giants, zonal flows remain very faint in the deeper dynamo region but increase in amplitude in the weakly conducting outer layer in some of our simulations. This suggests that the mid to high latitude jets

  2. Experimental studies on producer gas generation from wood waste in a downdraft biomass gasifier.

    Science.gov (United States)

    Sheth, Pratik N; Babu, B V

    2009-06-01

    A process of conversion of solid carbonaceous fuel into combustible gas by partial combustion is known as gasification. The resulting gas, known as producer gas, is more versatile in its use than the original solid biomass. In the present study, a downdraft biomass gasifier is used to carry out the gasification experiments with the waste generated while making furniture in the carpentry section of the institute's workshop. Dalbergia sisoo, generally known as sesame wood or rose wood is mainly used in the furniture and wastage of the same is used as a biomass material in the present gasification studies. The effects of air flow rate and moisture content on biomass consumption rate and quality of the producer gas generated are studied by performing experiments. The performance of the biomass gasifier system is evaluated in terms of equivalence ratio, producer gas composition, calorific value of the producer gas, gas production rate, zone temperatures and cold gas efficiency. Material balance is carried out to examine the reliability of the results generated. The experimental results are compared with those reported in the literature.

  3. Dynamic performance of power generation systems for off-shore oil and gas platforms

    DEFF Research Database (Denmark)

    Pierobon, Leonardo; Breuhaus, Peter; Haglind, Fredrik

    2014-01-01

    On off-shore oil and gas platforms two or more gas turbines typically support the electrical demand on site by operating as a stand-alone (island) power system. As reliability and availability are major concerns during operation, the dynamic performance of the power generation system becomes...... a crucial aspect for stable operation and prevention of unwanted shut down in case of disturbances in the local grid. This paper aims at developing and validating a dynamic model of the gas turbine-based power generation system installed on the Draugen off-shore oil and gas platform (located in the North...... Sea, Norway). The dynamic model of the SGT-500 gas turbine includes dynamic equations for the combustion chamber and for the high pressure, low pressure and turbine shafts. The low and high pressure compressors are modeled by using quasi steady-state conditions by scaling the maps of axial compressors...

  4. Gas generation from overmature Upper Jurassic source rocks, Northern Viking Graben

    Energy Technology Data Exchange (ETDEWEB)

    Erdmann, M.

    1999-09-01

    Laboratory experiments were performed on solvent extracted immature kerogen concentrates of 2 Upper Jurassic Heather and Draupne Formation samples. Information used to help choosing these samples from a larger sample set included observations on organic petrology, Rock Eval analysis, kerogen typing by pyrolysis-gas chromatography and determination of bulk generation kinetic parameters. The Draupne Formation sample is characterised by a marine type II kerogen with a strong aliphatic hydrocarbon signature and contents of organic sulphur. The Heather Formation has a high proportion of aromatic hydrocarbons and phenols due to higher contributions of terrigenous type III organic matter. Both samples revealed similar alkyl-chain lenght distributions pointing to similarities in the marine proportions of the kerogens. It was decided that detailed work on gas generation should consider these typical end-member kerogen compositions. The kinetics of primary and secondary gas (C{sub 1-5}) generation was recognised and kinetic parameters assigned to them. The results of extrapolations to a linear geological heating rate of 5.3 K/ma can be summarised in short as follows - Primary gas generation; Peak generation temperatures are higher for Heather Formation (T{sub max}=190 C, R{sub 0} appr. 1.7%) compared to Draupne Formation (T{sub max}=175 C, equivalent to R{sub 0} 1.3%) at 5.3 K/ma. - Secondary gas generation; Peak generation temperatures at 5.3 K/ma are 220 C for Heather Formation and 205 to 215 C for Draupne Formation secondary gas generation from the cracking of oil. These temperatures correspond to R{sub 0} values of 2.4% and 2.0%, respectively. The high temperature secondary gas formation from neoformed bitumen as detected for the Heather Formation is outstanding and is suggested to occur at very high temperatures (max appr. 250 C) for geological heating rates. (orig.)

  5. A study on the gas generation from radioactive waste packages under disposal conditions in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Park, Joo wan; Kim, Chang Lak; Choi, Heui Joo; Yoon, Jeong Hyoun [Korea Electric Power Corporation, Nuclear Environment Institute, Taejon (Korea, Republic of)

    1999-07-01

    In order to confirm the compliance to acceptance criteria , the performance of radioactive waste packages currently used at the nuclear power plants in Korea in aspect of gas generation is investigated. As the principal gas generation mechanisms radiolysis, corrosion of metals, and microbial activity of organic materials are considered. For calculating rates and total volumes of radiolytic hydrogen gas generated in waste packages a computer program that accommodates interactions among adjacent packages is used. Gas production due to metal corrosion and microbial degradation of Dry Active Waste (DAW) packages and the others is estimated over an assessment period of one thousand years under a given set of repository condition, respectively. Flammability hazard caused by radiolytic hydrogen formation inside a sealed waste package, pressure build-up inside the engineered barrier structure under repository condition is also assessed. (author)

  6. Numerical study of the generation of runaway electrons in a gas diode with a hot channel

    Energy Technology Data Exchange (ETDEWEB)

    Lisenkov, V. V., E-mail: lisenkov@iep.uran.ru [Institute of Electrophysics UrB RAS, 106 Amundsena St., Ekaterinburg 620012 (Russian Federation); Ural Federal University, 19 Mira St., Ekaterinburg 620002 (Russian Federation); Shklyaev, V. A., E-mail: shklyaev@to.hcei.tsc.ru [Institute of High Current Electronics SD RAS, 2/3 Akademichesky Avenue, 634055 Tomsk (Russian Federation); National Research Tomsk Polytechnic University, 30 Lenin Avenue, 634050 Tomsk (Russian Federation)

    2015-11-15

    A new method for increasing the efficiency of runaway electron beam generation in atmospheric pressure gas media has been suggested and theoretically proved. The method consists of creating a hot region (e.g., a spark channel or a laser plume) with a decreased numerical density of gas molecules (N) near the cathode. In this method, the ratio E/N (E—electric field strength) is increased by decreasing N instead of increasing E, as has been done in the past. The numerical model that is used allows the simultaneous calculation of the formation of a subnanosecond gas discharge and the generation of runaway electrons in gas media. The calculations have demonstrated the possibility of obtaining current pulses of runaway electrons with amplitudes of hundred of amperes and durations of more than 100 ps. The influence of the hot channel geometry on the parameters of the generated beam has been investigated.

  7. Health effects of living in the vicinity of the landfills

    Directory of Open Access Journals (Sweden)

    Katarzyna Lar

    2013-12-01

    Full Text Available Landfill sites are the easiest, the cheapest and the most common way of waste management and disposal. In the face of the increasing amount of waste, the dynamics of globalization and urbanization process, waste management is an important issue of ecological policy in highly developed countries. Landfill sites intensify environmental threats for the neighborhood and give rise to toxic substances which impair human health being released from the landfills. These are persistent organic pollutants (POPs, heavy metals and also biological gas, bioaerosols, bacteria and viruses. Scientists have conducted a lot of research to evaluate the impact of landfill sites on human health living in their vicinity. They found increased occurrence of congenital anomalies, increased risk of certain cancers and low birth weight of infants. The results of the studies didn’t deliver absolute proof of relation between the impact of landfill sites on the induction of cancer and other diseases. There is a necessity to conduct further research to evaluate the impact of landfill sites on people health living in the vicinity

  8. Groundwater geochemistry of a municipal landfill in Araras, SP

    Directory of Open Access Journals (Sweden)

    Carlos Frederico de Castro Alves 1

    2014-03-01

    Full Text Available A contaminated area associated with a residential unlined landfill, located in Araras, was investigated. The aim of this work was to develop a hydrogeological and geochemical conceptual model in order to identify the redox zones related to the landfill and to explain the main processes resulting from the impact of leachates on the local groundwaters and soil. The work consisted of a surface geological mapping, geophysical survey with electric tomography, logging of subsoil boreholes, an installation of monitoring wells and soil, gas, leachate and groundwater samples analyses. The results show that the Araras landfill is in the methanogenic phase and promotes alterations in local groundwater quality. The main parameters of environmental interest identified in the leachate were total dissolved solids, biochemical oxygen demand, ammonium, methane, Na, Cl, Fe, Mn, Ba, B, Co and Cd. According to criteria specifically developed for this landfill, the following redox zones were identified in the groundwater: (i aerobic, located upgradient from the landfill; (ii methanogenic, downgradient from the landfill; (iii iron and/or manganese reduction, located between the methanogenic zone and the Araras river. Bypassing the iron and/or manganese redox zone, the existence of a denitrification zone was inferred. Besides the redox reactions in these zones, other processes that mitigate the impact of leachate into groundwater were also discovered: dilution, degradation by the action of surface microorganisms, dispersion, ionic exchange, formation of organic and inorganic complexes, dissolution and precipitation.

  9. Site-specific criteria for the completion of landfill aftercare.

    Science.gov (United States)

    Laner, David; Fellner, Johann; Brunner, Paul H

    2012-09-01

    Municipal solid waste (MSW) landfills need to be managed after closure to assure long-term environmental compatibility. Aftercare can be completed when the authorities consider the landfill not likely to pose a threat to humans and the environment. In this work, a methodology for deriving site-specific aftercare completion criteria is presented and its application is illustrated via a case study. The evaluation method combines models addressing waste emission behavior, long-term barrier performance, and pollutant migration to assess the potential impact of landfill emissions on the environment. Based on the definition of acceptable impact levels at certain points of compliance, scenario- and pollutant-specific aftercare completion criteria are derived. The methodology was applied to a closed MSW landfill in Austria and potential aftercare durations were determined. While landfill gas emissions may become environmentally tolerable within decades at the site, leachate-related aftercare measures were expected to be necessary for centuries (primarily as a result of ammonium). Although the evaluation comes with large uncertainties, it allows for linking aftercare intensity and duration with respect to an environmentally compatible state of the landfill in the absence of aftercare. However, further case studies including regulatory review and acceptance are needed to use the methodology in a decision support tool on aftercare completion.

  10. Natural Gas, Wind and Nuclear Options for Generating Electricity in a Carbon Constrained World

    NARCIS (Netherlands)

    Kooten, van G.C.

    2012-01-01

    A linear programming model is used to examine the impact of carbon taxes on the optimal generation mix in the Alberta electrical system. The model permits decommissioning of generating assets with high carbon dioxide emissions and investment in new gas-fired, wind and, in some scenarios, nuclear

  11. Natural Gas, Wind and Nuclear Options for Generating Electricity in a Carbon Constrained World

    NARCIS (Netherlands)

    Kooten, van G.C.

    2012-01-01

    A linear programming model is used to examine the impact of carbon taxes on the optimal generation mix in the Alberta electrical system. The model permits decommissioning of generating assets with high carbon dioxide emissions and investment in new gas-fired, wind and, in some scenarios, nuclear cap

  12. Isotope-analytical results of a study of gas generation in L/ILW

    Science.gov (United States)

    Molnár, M.; Palcsu, L.; Svingor, É.; Futó, I.; Major, Z.; Rinyu, L.; Veres, M.

    2006-01-01

    The paper presents the results of a long-term measurement series using hermetic containers to make more precise quantitative estimation of the generation rates and radioactivity of the gas in a drum of low and intermediate level radioactive waste (L/ILW) packages. Development of special preparation lines and isotope-analytical measurements of the headspace gas samples were performed in the ATOMKI. Stable isotope measurements were executed from the CO2 and CH4 fractions by stable isotope ratio mass spectrometer. Noble gas (He) measurements were done by noble gas mass spectrometer. The tritium content of the vapour, H2 and CH4 fractions was measured in H2O chemical form by a low background liquid scintillation counter. The 14C content of the CO2 and CH4 fractions of the headspace gas samples was measured by a low background gas proportional counter system.

  13. A Decision Making Tool for Hazardous Waste Landfill Site Selection

    Directory of Open Access Journals (Sweden)

    P. Pandiyan

    2011-01-01

    Full Text Available Problem statement: Continuous global environmental crisis and degradation has been a challenge for the sustainability of living on earth. This threat was posed by industrialization, high products need, urbanization and population growth activities. As a result, the hazardous waste generation has tremendously increased. Approach: Landfill was one of the positive approaches to handle hazardous waste generated in great quantity. The appropriate selection of landfill site played a major role to remediate the hazardous waste materials. Attributes to be considered for decision-making were selected based on literature, observations with weightage assigned to each attribute following the pair wise comparison method and sensitivity index on a scale of 0 to 1 based on attribute measurement. The attributes were then grouped and ranked following Delphi approach. Results: In environmental assessment, field based study of three landfill sites such as Melakottaiyur, Pachaiyankuppam and Gummidipoondi in Tamil Nadu, India were selected and the sites scored a Risk Index (RI of 298.75, 369.05 and 408.25 respectively. In economical assessment, economic viability related attributes were analyzed and the three landfill site such as Pachaiyankuppam, Melakottaiyur and Gummidipoondi scored a RI of 86.1, 94.3 and 131.5 respectively. Conclusion/Recommendations: In environmental assessment the landfill sites were shortlisted. In order to achieve economic sustainability of the landfill, economic viability related attributes has to be analyzed with high priority and weightage in economical assessment.

  14. Sanitary Landfill Leachate Recycle and Environmental Problems at Selected Army Landfills: Lessons Learned

    Science.gov (United States)

    1986-09-01

    Benson, M. J. Staub , and M. A. Kamlys, Characteristics, Control and Treatment of Leachate at Military Irnstallations, !nterim Report N- 97/ADA097035...D. Smith, R. Pileccia, J. Handy, G. Gerdes, S. Kloster, G. Schanche, _. .1. fJanson, M. J. Staub , and M. A. Kamiya, Characteri.tic.i Control, and...Learned N 1. Do not construct buildings on top of or close to a closed landfill until methane gas production has stopped.... - 2. Note that explosive

  15. The Efficiency Improvement by Combining HHO Gas, Coal and Oil in Boiler for Electricity Generation

    Directory of Open Access Journals (Sweden)

    Chia-Nan Wang

    2017-02-01

    Full Text Available Electricity is an essential energy that can benefit our daily lives. There are many sources available for electricity generation, such as coal, natural gas and nuclear. Among these sources, coal has been widely used in thermal power plants that account for about 41% of the worldwide electricity supply. However, these thermal power plants are also found to be a big pollution source to our environment. There is a need to explore alternative electricity sources and improve the efficiency of electricity generation. This research focuses on improving the efficiency of electricity generation through the use of hydrogen and oxygen mixture (HHO gas. In this research, experiments have been conducted to investigate the combined effects of HHO gas with other fuels, including coal and oil. The results show that the combinations of HHO with coal and oil can improve the efficiency of electricity generation while reducing the pollution to our environment.

  16. Gas-phase generation of photoacoustic sound in an open environment.

    Science.gov (United States)

    Yönak, Serdar H; Dowling, David R

    2003-12-01

    The photoacoustic effect is commonly exploited for molecular spectroscopy, nondestructive evaluation, and trace gas detection. Photoacoustic sound is produced when a photoactive material absorbs electromagnetic radiation and converts it to acoustic waves. This article focuses on the generation of photoacoustic sound from thermal expansion of photoactive gases due to unsteady heating from a laser light source, and extends the work of prior studies on photoacoustic sound generation in an open environment. Starting with the forced free-space wave equation, a simple model is constructed for photoacoustic sounds produced by both acoustically distributed and compact gas clouds. The model accounts for laser absorption through the Lambert-Beer law and includes the effects of photoactive gas cloud characteristics (shape, size, and concentration distribution), but does not include molecular diffusion, thermal conduction, convection, or the effects of acoustic propagation through sound-absorbing inhomogeneous media. This model is compared to experimentally measured photoacoustic sounds generated by scanning a 10.6-micron carbon dioxide (CO2) laser beam through small clouds of a photoactive gas, sulfur hexafluoride (SF6). For the current investigation, the photoactive gas clouds are formed either by low flow-rate calibrated leak sources or by a laminar jet emerging from a 1.6-mm-diam tube. Model-measurement comparisons are presented over a 3- to 160-kHz bandwidth. Signal pulse shapes from simple gas cloud geometries are found to match calculated results when unmeasured gas cloud characteristics within the model are adjusted.

  17. Residential landfill remedial action construction case history

    Energy Technology Data Exchange (ETDEWEB)

    Creamer, P.D.; Martin, K.E. [RMT, Inc., Madison, WI (United States); Fahrney, J.S. [City of Madison, WI (United States)

    1995-12-31

    The City of Madison - Mineral Point Park is located on Madison`s west side within a well-established neighborhood on approximately 11 acres of open green space, which was formerly the Mineral Point Landfill. In 1994, a comprehensive remedial action construction project was implemented to more effectively extract methane gas and control gas migration, to minimize potential groundwater contamination, and to improve surface water run-off controls. This was accomplished by installing two new gas extraction systems, constructing a 4-foot-thick composite final cover with a geosynthetic subsurface drainage system, and adding 12 feet of relief and a storm sewer system to promote positive surface water drainage. While these features alone are not uncommon to many other landfills, the challenging aspect of this project was to install them in extreme proximity to homes, condominiums, and a school that were quickly developed shortly after the landfill closed. Some of the issues unique to this project due to the residential setting included strict noise, dust, and odor controls, easement negotiations, limited hours of operation, limited material storage areas, utility relocations and crossings, continuous operation of the existing gas extraction system, limited construction access, and increased health and safety concerns for the general public. The need to keep the neighboring residents informed, as well as to address their concerns and requests, was also a critical requirement in both the design and construction phases. This paper will review the design of the remedial action plan and present the construction process, highlighting the constructability issues encountered and the innovative means to overcome them. The program for communication with the neighbors throughout the design and construction phases will also be addressed.

  18. Next Generation Thermal Barrier Coatings for the Gas Turbine Industry

    Science.gov (United States)

    Curry, Nicholas; Markocsan, Nicolaie; Li, Xin-Hai; Tricoire, Aurélien; Dorfman, Mitch

    2011-01-01

    The aim of this study is to develop the next generation of production ready air plasma sprayed thermal barrier coating with a low conductivity and long lifetime. A number of coating architectures were produced using commercially available plasma spray guns. Modifications were made to powder chemistry, including high purity powders, dysprosia stabilized zirconia powders, and powders containing porosity formers. Agglomerated & sintered and homogenized oven spheroidized powder morphologies were used to attain beneficial microstructures. Dual layer coatings were produced using the two powders. Laser flash technique was used to evaluate the thermal conductivity of the coating systems from room temperature to 1200 °C. Tests were performed on as-sprayed samples and samples were heat treated for 100 h at 1150 °C. Thermal conductivity results were correlated to the coating microstructure using image analysis of porosity and cracks. The results show the influence of beneficial porosity on reducing the thermal conductivity of the produced coatings.

  19. Field assessment of semi-aerobic condition and the methane correction factor for the semi-aerobic landfills provided by IPCC guidelines

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Sangjae [Department of Civil and Environmental Engineering, College of Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742 (Korea, Republic of); Nam, Anwoo [Korea Environment Corporation, 42 Hwangyeong-ro, Seo-gu, Incheon 404-170 (Korea, Republic of); Yi, Seung-Muk [Department of Environmental Health, School of Public Health, Seoul National University, Seoul 151-742 (Korea, Republic of); Kim, Jae Young, E-mail: jaeykim@snu.ac.kr [Department of Civil and Environmental Engineering, College of Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742 (Korea, Republic of)

    2015-02-15

    Highlights: • CH{sub 4}/CO{sub 2} and CH{sub 4} + CO{sub 2}% are proposed as indices to evaluate semi-aerobic landfills. • A landfill which CH{sub 4}/CO{sub 2} > 1.0 is difficult to be categorized as semi-aerobic landfill. • Field conditions should be carefully investigated to determine landfill types. • The MCF default value for semi-aerobic landfills underestimates the methane emissions. - Abstract: According to IPCC guidelines, a semi-aerobic landfill site produces one-half of the amount of CH{sub 4} produced by an equally-sized anaerobic landfill site. Therefore categorizing the landfill type is important on greenhouse gas inventories. In order to assess semi-aerobic condition in the sites and the MCF value for semi-aerobic landfill, landfill gas has been measured from vent pipes in five semi-aerobically designed landfills in South Korea. All of the five sites satisfied requirements of semi-aerobic landfills in 2006 IPCC guidelines. However, the ends of leachate collection pipes which are main entrance of air in the semi-aerobic landfill were closed in all five sites. The CH{sub 4}/CO{sub 2} ratio in landfill gas, indicator of aerobic and anaerobic decomposition, ranged from 1.08 to 1.46 which is higher than the values (0.3–1.0) reported for semi-aerobic landfill sites and is rather close to those (1.0–2.0) for anaerobic landfill sites. The low CH{sub 4} + CO{sub 2}% in landfill gas implied air intrusion into the landfill. However, there was no evidence that air intrusion has caused by semi-aerobic design and operation. Therefore, the landfills investigated in this study are difficult to be classified as semi-aerobic landfills. Also MCF of 0.5 may significantly underestimate methane emissions compared to other researches. According to the carbon mass balance analyses, the higher MCF needs to be proposed for semi-aerobic landfills. Consequently, methane emission estimate should be based on field evaluation for the semi-aerobically designed landfills.

  20. Modeling on the gas-generating amount of sediments hydrate-bearing

    Energy Technology Data Exchange (ETDEWEB)

    Gong, J.M.; Cao, Z.M. [Ocean Univ. of China, Qingdao (China); Jian-Ming, G.; Chen, J.W. [Qingdao Inst. of Marine Geology, Qingdao (China); Zhang, M.; Yang, G.F. [Yangtze Univ., Jingzhou (China); Li, J. [PetroChina, HeBei (China). Langfang Branch, Research Inst. of Petroleum Exploration and Development

    2008-07-01

    Gas hydrate is a form of clean fossil energy. It has the characteristics of extensive distribution, large reserve, high-energy capacity and less pollution after combustion. It also has a great energy value, generating interest from governments and scientists in different countries. This paper discussed a study in which methane generating hydrate-bearing sediments were investigated. A total of 58 sediment samples from 4 sites of ODP Leg 204 were modeled by 5 temperature points. ODP Leg 204 lies offshore western United States, in the Hydrate Ridge region (Oregon) of the Pacific. It is one of the most studied areas and clearest about hydrate distribution in the world. The paper described the study area and sample preparation. It also discussed the modeling and geochemical characteristics of the gas-generating samples. A model section revealed bacteria species, substrate deployment, selection of culture flask, and sample culture. The geochemical characteristics of the gas-generating samples were also described. It was concluded that the sediments within 1,200 meters below the seafloor were the main gas source of the biogenic gas hydrate. The organic matter abundance of the sediments at this depth and the migration passage of the fluids in the strata were important for the formation and preservation of the gas hydrate deposits. 21 refs., 1 tab., 6 figs.

  1. Combined gas/steam turbine power plants with coal fired steam generator

    Energy Technology Data Exchange (ETDEWEB)

    Krueger, H.J.; Weirich, P.H. [ABB Kraftwerke AG, Mannheim (Germany)

    1994-12-31

    The combination of coal fired steam power plants with natural gas fired gas turbines results in an essential efficiency increase, up to 50%, requiring a portion of around one third of the fuel heat input in form of natural gas. There are two basic types of circuit arrangements in this category: in a topping process the gas turbine is connected to the steam generator on the gas side, and in a compound cycle power plant gas turbine and steam circuit are connected to each other on the water/steam side via a heat recovery steam generator. If comparable design parameters are applied slightly higher plant efficiencies can be obtained with the topping process. With respect to a higher power plant availability it is possible to operate both types of circuit arrangement without gas turbine. The specific investment cost of such combined cycle power plants is lower than that of corresponding steam power plants. Hence, they can represent economical solutions as far as the price ratio between natural gas and coal is not extremely high. In ecological respects, the advantage of this combination is a reduction of the specific CO{sub 2} emission by around 20-25%, compared with pure steam power plants. 1 ref., 9 figs., 2 tabs.

  2. Electricity Generation Characteristics of Microbial Fuel Cell ith Landfill Leachate as Fuel%以垃圾渗滤液为燃料的微生物燃料电池产电性能

    Institute of Scientific and Technical Information of China (English)

    张晓艳; 滕洪辉

    2011-01-01

    The double-chamber microbial fuel cell ( DCMFC ) with landfill leachate from some refuse dump of Siping City of Jilin Province as fuel was designed in the system with the bacteria in the titanium anode chamber separated from the titanium cathode chamber by a salt bridge. The effects of cathode chamber solution parameters on the electricity generation performance of DCMFC were researched. The results show that the DCMFC output power density is 12. 074 W/m2, open-circuit voltage is 1.13 V, internal resistance is 76. 868 O, under cathode chamber solution optimum conditions of 30 'C , 1.0 g/L H2O2, pH =2. 5, and 0. 5 g/L Na2SO4. After the DCMFC was continuously running for 30 days, the COD removal rate of landfill leachate reached to 95% , the adjust of cathode chamber operational parameters can improve the microbial fuel cell electricit generation.%以吉林省四平市某垃圾场渗滤液为燃料,纯钛板为负载微生物阳极和阴极,用盐桥转移电子方式组建双室微生物燃料电池(DCMFC).研究阴极室溶液电子受体质量浓度、pH值、温度等因素对输出功率密度、开路电压、内阻等电池性能的影响,并考察了对垃圾渗滤液的处理效果.实验结果表明,阴极溶液以1.0 g/L双氧水为电子受体,在pH=2.5、ρ(硫酸钠)=0.5 g/L、温度约为30 ℃的最佳实验条件下,该微生物燃料电池的输出功率密度达12.074 W/m2,开路电压为1.13 V,内阻为76.868 Ω.经过连续30 d的运行,垃圾渗滤液化学需氧量(COD)去除率达95%,表明选择恰当的阴极室溶液能提高微生物燃料电池的产电性能.

  3. Investigation of a catalytic gas generator for the Space Shuttle APU. [hydrazine Auxiliary Propulsion Unit

    Science.gov (United States)

    Emmons, D. L.; Huxtable, D. D.; Blevins, D. R.

    1974-01-01

    An investigation was conducted to establish the capability of a monopropellant hydrazine catalytic gas generator to meet the requirements specified for the Space Shuttle APU. Detailed analytical and experimental studies were conducted on potential problem areas including long-term nitriding effects on materials, design variables affecting catalyst life, vehicle vibration effects, and catalyst oxidation/contamination. A full-scale gas generator, designed to operate at a chamber pressure of 750 psia and a flow rate of 0.36 lbm/sec, was fabricated and subjected to three separate life test series. The objective of the first test series was to demonstrate the capability of the gas generator to successfully complete 20 simulated Space Shuttle missions in steady-state operation. The gas generator was then refurbished and subjected to a second series of tests to demonstrate the pulse-mode capability of the gas generator during 20 simulated missions. The third series of tests was conducted with a refurbished reactor to further demonstrate pulse-mode capability with a modified catalyst bed.

  4. Gas generation from Hanford grout samples. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Jonah, C.D.; Kapoor, S.: Matheson, M.S.; Mulac, W.A.; Meisel, D.

    1994-03-01

    The radiolytic yields of H{sub 2}, N{sub 2}, O{sub 2}, N{sub 2}O, and CO from two batches of WHC-supplied samples of grouted simulated waste have been {gamma} irradiated at several dose rates (0.025, 0.63 and 130 krad/h for H{sub 2} and 130 krad/h for all other gases). In one batch, the liquid waste simulant that was added to the grout included the original components that were added to Tank 102-AP (labeled ``virgin``waste.) The second batch included a similar liquid waste simulant that was preirradiated to 35 Mrad prior to incorporation into the grout. It is believed that the preirradiated samples more closely represent radioactive waste that was stored in the tank for several years. The lowest dose rate corresponds approximately to that expected in the grout; with the high dose rate, doses equivalent to about 85 years storage in grout vaults were achieved. Most of the results on the batch of virgin samples have been reported recently (Report ANL 93/42). Here we report the results from the batch of preirradiated grout samples and compare the results from the two batches. The radiolytic yields of H{sub 2} and N{sub 2} are lower in the preirradiated than in the virgin grout. On the other hand G(O{sub 2}) is higher in the preirradiated samples: 0.078 vs. 0.026. The yield of nitrous oxide is essentially the same, G(N{sub 2}O) =0.010, in both. The yields measured from both batches are significantly higher than previously reported values. At 90{degrees}C similar amounts of H{sub 2} were generated thermally from both batches of grout, whereas the total amounts of N{sub 2} and N{sub 2}O were larger for the preirradiated than for the virgin grout samples. At lower temperatures the rate of generation was hardly measurable. Mass spectrometric analysis suggests that NO is thermally (but not radiolytically) released from the grout samples.

  5. Evaluating greenhouse gas impacts of organic waste management options using life cycle assessment.

    Science.gov (United States)

    Kong, Dung; Shan, Jilei; Iacoboni, Mario; Maguin, Stephen R

    2012-08-01

    Efforts to divert organics away from landfills are viewed by many as an important measure to significantly reduce the climate change impacts of municipal solid waste management. However, the actual greenhouse gas (GHG) impacts of organics diversion from landfills have yet to be thoroughly evaluated and whether such a diversion provides significant environmental benefits in terms of GHG impacts must be answered. This study, using California-specific information, aimed to analyse the GHG impacts of organics diversion through a life-cycle assessment (LCA). This LCA considered all aspects of organics management including transportation, materials handling, GHG emissions, landfill gas capture/utilization, energy impacts, and carbon sequestration. The LCA study evaluated overall GHG impacts of landfilling, and alternative management options such as composting and anaerobic digestion for diverted organic waste. The LCA analysis resulted in net GHG reductions of 0.093, 0.048, 0.065 and 0.073 tonnes carbon equivalent per tonne organic waste for landfilling, windrow composting, aerated static pile composting, and anaerobic digestion, respectively. This study confirms that all three options for organics management result in net reductions of GHG emissions, but it also shows that organics landfilling, when well-managed, generates greater GHG reductions. The LCA provides scientific insight with regards to the environmental impacts of organics management options, which should be considered in decision and policy-making. The study also highlights the importance of how site and case-specific conditions influence project outcomes when considering organic waste management options.

  6. Generation of ethylene tracer by noncatalytic pyrolysis of natural gas at elevated pressure

    Science.gov (United States)

    Lu, Y.; Chen, S.; Rostam-Abadi, M.; Ruch, R.; Coleman, D.; Benson, L.J.

    2005-01-01

    There is a critical need within the pipeline gas industry for an inexpensive and reliable technology to generate an identification tag or tracer that can be added to pipeline gas to identify gas that may escape and improve the deliverability and management of gas in underground storage fields. Ethylene is an ideal tracer, because it does not exist naturally in the pipeline gas, and because its physical properties are similar to the pipeline gas components. A pyrolysis process, known as the Tragen process, has been developed to continuously convert the ???2%-4% ethane component present in pipeline gas into ethylene at common pipeline pressures of 800 psi. In our studies of the Tragen process, pyrolysis without steam addition achieved a maximum ethylene yield of 28%-35% at a temperature range of 700-775 ??C, corresponding to an ethylene concentration of 4600-5800 ppm in the product gas. Coke deposition was determined to occur at a significant rate in the pyrolysis reactor without steam addition. The ?? 13C isotopic analysis of gas components showed a ?? 13C value of ethylene similar to ethane in the pipeline gas, indicating that most of the ethylene was generated from decomposition of the ethane in the raw gas. However, ?? 13C isotopic analysis of the deposited coke showed that coke was primarily produced from methane, rather than from ethane or other heavier hydrocarbons. No coke deposition was observed with the addition of steam at concentrations of > 20% by volume. The dilution with steam also improved the ethylene yield. ?? 2005 American Chemical Society.

  7. Ecological balance of power generation from sewage gas; Oekobilanz Klaergasverstromung

    Energy Technology Data Exchange (ETDEWEB)

    Ronchetti, C.; Bienz, P.; Pridal, R.

    2002-07-01

    This report for the Swiss Federal Office of Energy (SFOE) presents the ecological balance made for the production of electrical power from biogas that is produced in waste water treatment plants. The study was needed as the basis for deciding if power thus generated could be certified to the strict 'Naturemade Star' standards. This label is used to designate 'green' power. The report briefly describes the processes usually used in the treatment of sewage sludge, the energy-intensive aerobic and anaerobic digestion, which produces biogas. The ecological factors of the two processes were assessed using the Eco-Indicator 99 tool. The results are discussed, which showed that a typical modern waste water treatment plant is significantly better as far as energy is concerned than older examples of plant (e.g. those built in 1995) as far as ecological impact is concerned. Also, the study addresses other forms of biogas use, like, for example, its use as a fuel for vehicles.

  8. Micro- and Nanoscale Energetic Materials as Effective Heat Energy Sources for Enhanced Gas Generators.

    Science.gov (United States)

    Kim, Sang Beom; Kim, Kyung Ju; Cho, Myung Hoon; Kim, Ji Hoon; Kim, Kyung Tae; Kim, Soo Hyung

    2016-04-13

    In this study, we systematically investigated the effect of micro- and nanoscale energetic materials in formulations of aluminum microparticles (Al MPs; heat source)/aluminum nanoparticles (Al NPs; heat source)/copper oxide nanoparticles (CuO NPs; oxidizer) on the combustion and gas-generating properties of sodium azide microparticles (NaN3 MPs; gas-generating agent) for potential applications in gas generators. The burn rate of the NaN3 MP/CuO NP composite powder was only ∼0.3 m/s. However, the addition of Al MPs and Al NPs to the NaN3 MP/CuO NP matrix caused the rates to reach ∼1.5 and ∼5.3 m/s, respectively. In addition, the N2 gas volume flow rate generated by the ignition of the NaN3 MP/CuO NP composite powder was only ∼0.6 L/s, which was significantly increased to ∼1.4 and ∼3.9 L/s by adding Al MPs and Al NPs, respectively, to the NaN3 MP/CuO NP composite powder. This suggested that the highly reactive Al MPs and NPs, with the assistance of CuO NPs, were effective heat-generating sources enabling the complete thermal decomposition of NaN3 MPs upon ignition. Al NPs were more effective than Al MPs in the gas generators because of the increased reactivity induced by the reduced particle size. Finally, we successfully demonstrated that a homemade airbag with a specific volume of ∼140 mL could be rapidly and fully inflated by the thermal activation of nanoscale energetic material-added gas-generating agents (i.e., NaN3 MP/Al NP/CuO NP composites) within the standard time of ∼50 ms for airbag inflation.

  9. Microbial Gas Generation Under Expected Waste Isolation Pilot Plant Repository Conditions: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Gillow, J.B.; Francis, A.

    2011-07-01

    Gas generation from the microbial degradation of the organic constituents of transuranic (TRU) waste under conditions expected in the Waste Isolation Pilot Plant (WIPP) was investigated. The biodegradation of mixed cellulosic materials and electron-beam irradiated plastic and rubber materials (polyethylene, polyvinylchloride, hypalon, leaded hypalon, and neoprene) was examined. We evaluated the effects of environmental variables such as initial atmosphere (air or nitrogen), water content (humid ({approx}70% relative humidity, RH) and brine inundated), and nutrient amendments (nitogen phosphate, yeast extract, and excess nitrate) on microbial gas generation. Total gas production was determined by pressure measurement and carbon dioxide (CO{sub 2}) and methane (CH{sub 4}) were analyzed by gas chromatography; cellulose degradation products in solution were analyzed by high-performance liquid chromatography. Microbial populations in the samples were determined by direct microscopy and molecular analysis. The results of this work are summarized.

  10. Methane emissions from a Californian landfill, determined from airborne remote sensing and in situ measurements

    Directory of Open Access Journals (Sweden)

    S. Krautwurst

    2017-09-01

    Full Text Available Fugitive emissions from waste disposal sites are important anthropogenic sources of the greenhouse gas methane (CH4. As a result of the growing world population and the recognition of the need to control greenhouse gas emissions, this anthropogenic source of CH4 has received much recent attention. However, the accurate assessment of the CH4 emissions from landfills by modeling and existing measurement techniques is challenging. This is because of inaccurate knowledge of the model parameters and the extent of and limited accessibility to landfill sites. This results in a large uncertainty in our knowledge of the emissions of CH4 from landfills and waste management. In this study, we present results derived from data collected during the research campaign COMEX (CO2 and MEthane eXperiment in late summer 2014 in the Los Angeles (LA Basin. One objective of COMEX, which comprised aircraft observations of methane by the remote sensing Methane Airborne MAPper (MAMAP instrument and a Picarro greenhouse gas in situ analyzer, was the quantitative investigation of CH4 emissions. Enhanced CH4 concentrations or CH4 plumes were detected downwind of landfills by remote sensing aircraft surveys. Subsequent to each remote sensing survey, the detected plume was sampled within the atmospheric boundary layer by in situ measurements of atmospheric parameters such as wind information and dry gas mixing ratios of CH4 and carbon dioxide (CO2 from the same aircraft. This was undertaken to facilitate the independent estimation of the surface fluxes for the validation of the remote sensing estimates. During the COMEX campaign, four landfills in the LA Basin were surveyed. One landfill repeatedly showed a clear emission plume. This landfill, the Olinda Alpha Landfill, was investigated on 4 days during the last week of August and first days of September 2014. Emissions were estimated for all days using a mass balance approach. The derived emissions vary between 11

  11. Registration and optimization of gas production from sealed waste containing units in landfills. Registrering og optimering af gasproduktion fra lukkede affaldsceller i lossepladser

    Energy Technology Data Exchange (ETDEWEB)

    Willumsen, H.C.

    1990-05-15

    The aim was to evaluate the production of biogas from household wastes in order to estimate the feasibility of establishing gas producing systems in connection with Danish municipal refuse dumps. Two sealed units, one containing ordinary (sorted) household waste, the other household waste which included garden rubbish were investigated with this aim in mind. It was found difficult to keep the sealed units and the pump system ''gastight''. An accurate estimation of brutto gas production was not arrived at, partly because one of the units was producing acid and not methane and the other had not reached the methane producing stage at the time. Yet significant, applicable, information as to the microbiological processes was obtained thus validating further research on this subject. (AB) 12 refs.

  12. 77 FR 52553 - Standards of Performance for Stationary Gas Turbines; Standards of Performance for Stationary...

    Science.gov (United States)

    2012-08-29

    ... gas), coal bed methane, closed landfills, etc. Similar to biogas, substantial environmental benefits... loads or devices powered by electricity, steam, hot water or directly by the gross output of the... sufficient. In addition, we are proposing to recognize the environmental benefit of electricity generated...

  13. Entropy generation in a channel resembling gas turbine cooling passage: Effect of rotation number and density ratio on entropy generation

    Indian Academy of Sciences (India)

    M Basha; M Al-Qahtani; B S Yilbas

    2009-06-01

    Flow into a passage resembling a gas turbine blade cooling passage is considered and entropy generation rate in the passage is examined for unique rotation number and density ratios. In the simulations, leading and trailing walls of the passage are assumed to be at constant temperature. A control volume approach is introduced to discretize the governing equations of flow, heat transfer, and entropy generation. Reynolds stress turbulence model is accommodated in the simulation to account for the turbulence. The study is extended to include two rotational speeds and three density ratios. The passage aspect ratio is kept 10:1. It is found that volumetric entropy generation rate attains high values at passage inlet due to attainment of high temperature gradient in this region. Increasing rotation number and density ratio enhances volumetric entropy generation rate in the passage.

  14. Analytical investigation of thermal barrier coatings on advanced power generation gas turbines

    Science.gov (United States)

    Amos, D. J.

    1977-01-01

    An analytical investigation of present and advanced gas turbine power generation cycles incorporating thermal barrier turbine component coatings was performed. Approximately 50 parametric points considering simple, recuperated, and combined cycles (including gasification) with gas turbine inlet temperatures from current levels through 1644K (2500 F) were evaluated. The results indicated that thermal barriers would be an attractive means to improve performance and reduce cost of electricity for these cycles. A recommended thermal barrier development program has been defined.

  15. Generation of phosphine gas for the control of grain storage pests

    OpenAIRE

    Zhao, B.X.

    2010-01-01

    The phosphine generator is a device for rapid production of phosphine (PH₃) gas to be introduced into grain storage. The aluminum phosphide (ALP) tablets are used as raw material and its effective constituent is 56%. When the aluminum phosphide and water are brought into contact a hydrolyzation reaction takes place to produce the phosphine gas. Controlling the reaction temperature, reaction pressure and the dosage of aluminum phosphide immersed in the water, the hydrolyzation reaction can be ...

  16. Landfill Construction and Capacity Expansion

    NARCIS (Netherlands)

    Andre, F.J.; Cerda, E.

    2003-01-01

    We study the optimal capacity and lifetime of landfills taking into account their sequential nature.Such an optimal capacity is characterized by the so-called Optimal Capacity Condition.Particular versions of this condition are obtained for two alternative settings: first, if all the landfills are t

  17. Stabilizing Waste Materials for Landfills

    Science.gov (United States)

    Environmental Science and Technology, 1977

    1977-01-01

    The test procedures used to evaluate the suitability of landfilled materials of varying stability and to determine the leachate from such materials are reviewed. A process for stabilizing a mixture of sulfur dioxide sludge, fly ash, and bottom ash with lime and other additives for deposition in landfills is detailed. (BT)

  18. 联合型生物反应器填埋场厌氧单元产甲烷规律研究%Study on Methane Generation Regulation in Anaerobic-semiaerobic Bioreactor Anaerobic Landfill

    Institute of Scientific and Technical Information of China (English)

    宋豪娟; 刘丹; 韩智勇; 王宁

    2013-01-01

    基于模拟实验,研究新型厌氧型生物反应器(ANBL)-准好氧矿化垃圾联合型生物反应器(SAABR)厌氧单元产气速率、产气CH4含量以及累计产CH4量的变化规律.实验证明,由于回灌复氧后的渗滤液甲烷菌的活性受到抑制,AN-SABL中的厌氧填埋单元的产气受到了抑制,但较高的回灌频率使得渗滤液与微生物的接触机会增多,利于垃圾产气;综合分析产气CH4含量、渗滤液COD和渗滤液pH值,在此判断3个ANBL CH4发酵阶段分别为705~820,690~ 800和660~740 d,该阶段产气φ(CH4)最大值分别为78.6%,74.1%和71.5%.建立了ANBL累计产CH4量的指数增长模型,对生物反应器CH.的收集和利用有重要意义.%Alstract:Based on the experimental simulation device,the regulation of the gas production,content of methane and cumulative methane production in the anaerobic-semiaerobic bioreactor landfill were studied.It was proved that,methane germ of the activity was repressed because of leachate recirculation to infuse to reply oxygen,and gas production in the ANSABL was repressed,but higher leachate recirculation frequency improved the contact opportunity of leachate and microorganism,then benefit gas production; comprehensively analyzed the gas methane content,leachate COD and leachate pH,this research judged three ANBL methane ferments stage were 705 ~ 820 d,690 ~ 800 d and 660 ~ 740 d,that stage the biggest content of methane is 78.6%,74.1% and 71.5%.The index number growth model of the ANBL cumulative methane was built up,which was important to collections and exploitation of bioreactor methane.

  19. Nondestructive Evaluation of the J-2X Direct Metal Laser Sintered Gas Generator Discharge Duct

    Science.gov (United States)

    Esther, Elizabeth A.; Beshears, Ronald D.; Lash, Rhonda K.

    2012-01-01

    The J-2X program at NASA's Marshall Space Flight Center (MSFC) procured a direct metal laser sintered (DMLS) gas generator discharge duct from Pratt & Whitney Rocketdyne and Morris Technologies for a test program that would evaluate the material properties and durability of the duct in an engine-like environment. DMLS technology was pursued as a manufacturing alternative to traditional techniques, which used off nominal practices to manufacture the gas generator duct's 180 degree turn geometry. MSFC's Nondestructive Evaluation (NDE) Team performed radiographic, ultrasonic, computed tomographic, and fluorescent penetrant examinations of the duct. Results from the NDE examinations reveal some shallow porosity but no major defects in the as-manufactured material. NDE examinations were also performed after hot-fire testing the gas generator duct and yielded similar results pre and post-test and showed no flaw growth or development.

  20. Preliminary Evaluation of Gas Generation from the Korean LILW Repository using the SMOGG Code

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Suk Hoon; Kim, Ju Youl [FNC Technology, Yongin (Korea, Republic of); Park, Jin Beak; Lee, Sun Joung [Korea Radioactive Waste Management Corporation, Daejeon (Korea, Republic of)

    2010-10-15

    For the permanent disposal of 100,000 drums of LILW (Low- and Intermediate-Level radioactive Waste) for the first stage of operation (800,000 drums in the long run) in Korea, the rock-cavern repository is being constructed at Gyeongju city. During the lifetime and post-closure period of the repository, it is expected that bulk gases (e.g. hydrogen, carbon dioxide, methane, etc.) are mainly produced by various mechanisms such as the metal corrosion, microbial degradation of organic materials, and radiolysis. Since gases generated have the potential threat to overpressurize the repository, which can promote the transport of radionuclide contained in groundwater and gas, it is necessary to simulate the features of gas generation from the repository using the appropriate computer code prior to the start of operation. This paper describes the preliminary evaluation of gas generation from the repository using the SMOGG code

  1. Development of the Next Generation Gas Trap for the Space Station Internal Thermal Control System

    Science.gov (United States)

    Leimkuehler, Thomas O.; Spelbring, Chris; Reeves, Daniel R.; Holt, James M.

    2003-01-01

    The current dual-membrane gas trap is designed to remove non-condensed gases (NCG) from the Internal Thermal Control System (ITCS) coolant on board the International Space Station (ISS). To date it has successfully served its purpose of preventing depriming, overspeed, and shutdown of the ITCS pump. However, contamination in the ITCS coolant has adversely affected the gas venting rate and lifetime of the gas trap, warranting a development effort for a next-generation gas trap. Design goals are to meet or exceed the current requirements to (1) include greater operating ranges and conditions, (2) eliminate reliance on the current hydrophilic tube fabrication process, and (3) increase operational life and tolerance to particulate and microbial growth fouling. In addition, the next generation gas trap will essentially be a 'dropin" design such that no modifications to the ITCS pump package assembly (PPA) will be required, and the implementation of the new design will not affect changes to the ITCS operational conditions, interfaces, or software. This paper will present the initial membrane module design and development work which has included (1) a trade study among several conceptual designs, (2) performance modeling of a hydrophobic-only design, and (3) small-scale development test data for the hydrophobic-only design. Testing has shown that the hydrophobic-only design is capable of performing even better than the current dual-membrane design for both steady-state gas removal and gas slug removal.

  2. Using Probability of Exceedance to Compare the Resource Risk of Renewable and Gas-Fired Generation

    Energy Technology Data Exchange (ETDEWEB)

    Bolinger, Mark [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2017-08-01

    Of the myriad risks surrounding long-term investments in power plants, resource risk is one of the most difficult to mitigate, and is also perhaps the risk that most-clearly distinguishes renewable generation from natural gas-fired generation. For renewable generators like wind and solar projects, resource risk manifests as a quantity risk—i.e., the risk that the quantity of wind and insolation will be less than expected.i For gas-fired generators (i.e., a combined-cycle gas turbine or “CCGT”), resource risk manifests primarily as a price risk—i.e., the risk that natural gas will cost more than expected. Most often, resource risk—and natural gas price risk in particular—falls disproportionately on utility ratepayers, who are typically not well-equipped to manage this risk. As such, it is incumbent upon utilities, regulators, and policymakers to ensure that resource risk is taken into consideration when making or approving resource decisions, or enacting policies that influence the development of the electricity sector more broadly.

  3. Trends in sustainable landfilling in Malaysia, a developing country.

    Science.gov (United States)

    Fauziah, S H; Agamuthu, P

    2012-07-01

    In Malaysia, landfills are being filled up rapidly due to the current daily generation of approximately 30,000 tonnes of municipal solid waste. This situation creates the crucial need for improved landfilling practices, as sustainable landfilling technology is yet to be achieved here. The objective of this paper is to identify and evaluate the development and trends in landfilling practices in Malaysia. In 1970, the disposal sites in Malaysia were small and prevailing waste disposal practices was mere open-dumping. This network of relatively small dumps, typically located close to population centres, was considered acceptable for a relatively low population of 10 million in Malaysia. In the 1980s, a national programme was developed to manage municipal and industrial wastes more systematically and to reduce adverse environmental impacts. The early 1990s saw the privatization of waste management in many parts of Malaysia, and the establishment of the first sanitary landfills for MSW and an engineered landfill (called 'secure landfill' in Malaysia) for hazardous waste. A public uproar in 2007 due to contamination of a drinking water source from improper landfilling practices led to some significant changes in the government's policy regarding the country's waste management strategy. Parliament passed the Solid Waste and Public Cleansing Management (SWPCM) Act 2007 in August 2007. Even though the Act is yet to be implemented, the government has taken big steps to improve waste management system further. The future of the waste management in Malaysia seems somewhat brighter with a clear waste management policy in place. There is now a foundation upon which to build a sound and sustainble waste management and disposal system in Malaysia.

  4. Aeroderivative Pratt & Whitney FT8-3 gas turbine – an interesting solution for power generation

    Directory of Open Access Journals (Sweden)

    Sorinel-Gicu TALIF

    2011-03-01

    Full Text Available The intermediate load electric power stations become more and more interesting for theelectric power market in Romania. In this context, the Combined Cycle Power Plants came as a veryattractive solution. This paper presents the results of a study regarding the use of the aeroderivativePratt & Whitney FT8-3 gas turbine, available in Romania, for the electric power generation in aCombined Cycle Power Plant. It is also analyzed the Combined Heat in Power generation with FT8-3gas turbine when saturated steam or hot water are required.

  5. Evaluation of methane emissions from Palermo municipal landfill: Comparison between field measurements and models.

    Science.gov (United States)

    Di Bella, Gaetano; Di Trapani, Daniele; Viviani, Gaspare

    2011-08-01

    Methane (CH(4)) diffuse emissions from Municipal Solid Waste (MSW) landfills represent one of the most important anthropogenic sources of greenhouse gas. CH(4) is produced by anaerobic biodegradation of organic matter in landfilled MSW and constitutes a major component of landfill gas (LFG). Gas recovery is a suitable method to effectively control CH(4) emissions from landfill sites and the quantification of CH(4) emissions represents a good tool to evaluate the effectiveness of a gas recovery system in reducing LFG emissions. In particular, LFG emissions can indirectly be evaluated from mass balance equations between LFG production, recovery and oxidation in the landfill, as well as by a direct approach based on LFG emission measurements from the landfill surface. However, up to now few direct measurements of landfill CH(4) diffuse emissions have been reported in the technical literature. In the present study, both modeling and direct emission measuring methodologies have been applied to the case study of Bellolampo landfill located in Palermo, Italy. The main aim of the present study was to evaluate CH(4) diffuse emissions, based on direct measurements carried out with the flux accumulation chamber (static, non-stationary) method, as well as to obtain the CH(4) contoured flux map of the landfill. Such emissions were compared with the estimate achieved by means of CH(4) mass balance equations. The results showed that the emissions obtained by applying the flux chamber method are in good agreement with the ones derived by the application of the mass balance equation, and that the evaluated contoured flux maps represent a reliable tool to locate areas with abnormal emissions in order to optimize the gas recovery system efficiency.

  6. Spent Nuclear Fuel Project (SNFP) gas generation from N-Fuel in multi-canister overpacks

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, T.D.

    1996-08-01

    During the conversion from wet pool storage for spent nuclear fuel at Hanford, gases will be generated from both radiolysis and chemical reactions. The gas generation phenomenon needs to be understood as it applies to safety and design issues,specifically over pressurization of sealed storage containers,and detonation/deflagration of flammable gases. This study provides an initial basis to predict the implications of gas generation on the proposed functional processes for spent nuclear fuel conversion from wet to dry storage. These projections are based upon examination of the history of fuel manufacture at Hanford, irradiation in the reactors, corrosion during wet pool storage, available fuel characterization data and available information from literature. Gas generation via radiolysis and metal corrosion are addressed. The study examines gas generation, the boundary conditions for low medium and high levels of sludge in SNF storage/processing containers. The functional areas examined include: flooded and drained Multi-Canister Overpacks, cold vacuum drying, shipping and staging and long term storage.

  7. Outlook of natural gas thermal generation; A geracao termeletrica a gas natural e o PPT (Programa Prioritario de Termoeletricidade)

    Energy Technology Data Exchange (ETDEWEB)

    Felix, Makyo A.; Correia Junior, Clovis [Bahiagas - Companhia de Gas da Bahia, Salvador, BA (Brazil); Garcia, Celestino B. [Agencia Nacional do Petroleo, Gas Natural e Biocombustiveis (ANP), Rio de Janeiro, RJ (Brazil)

    2004-07-01

    The national integrated system has always had hydroelectricity as its main source of energy supply. However, a long period of lack of investment in sector put the country in a complacent position in which there was an overabundance of energy supply. The subsequent power shortage of 2001, led to a long term strategy of assuring supply with perspective of attending demand quickly and guaranteeing the security of the system by exploiting a source of energy rarely used in the country: thermal energy using natural gas. For this reason, the federal government launched the PPT Program (Priority Program of Thermoelectricity) with the aim of stimulating investment in thermo electrical plants, utilizing natural gas which is cheaper and less polluting. However, investment by the private sector did not fulfill expectations even with regular production, financial incentives of the government and favourable points through thermal generation using natural gas. Therefore, PETROBRAS decided to assume the risk and form partnerships to assure investments in thermo electrical plants. In the strategy of implanting thermal plants, who would be responsible to carry out this process along with guarantees of supply, was not properly defined. The establishment of thermal plants without a regulatory framework and undefined investment plan, compromises the essence of its creation. It is from this angle, that evaluates the recent collapse of energy of the Northeast region and the effective implantation of thermoelectricity utilizing natural gas. (author)

  8. Construction and evaluation of simulated pilot scale landfill lysimeter in Bangladesh.

    Science.gov (United States)

    Rafizul, Islam M; Howlader, Milon Kanti; Alamgir, Muhammed

    2012-11-01

    This research concentrates the design, construction and evaluation of simulated pilot scale landfill lysimeter at KUET campus, Khulna, Bangladesh. Both the aerobic and anaerobic conditions having a base liner and two different types of cap liner were simulated. After the design of a reference cell, the construction of landfill lysimeter was started in January 2008 and completed in July 2008. In all construction process locally available civil construction materials were used. The municipal solid waste (MSW) of 2800-2985 kg having the total volume of 2.80 m(3) (height 1.6 m) and moisture content of 65% was deposited in each lysimeter by applying required compaction energy. In contrast, both the composition in terms of methane (CH(4)), carbon dioxide (CO(2)) and oxygen (O(2)) as well as the flow rate of landfill gas (LFG) generated from MSW in landfill lysimeter were measured and varied significantly in relation to the variation of lysimeter operational condition. Moreover, anaerobic lysimeter-C shows the highest composition of LFG in compare to the anaerobic lysimeter-B due to the providing of lower compaction of cap liner in anaerobic lysimeter-C. Here, it is interesting to note that in absence of compacted clay liner (CCL) and hence percolation of rainwater that facilitates rapid degradation of MSW in aerobic lysimeter-A has resulted in the highest settlement than that of anaerobic landfill lysimeter-B and C. Moreover, in case of anaerobic lysimeter-B and C, the leachate generation was lower than that of aerobic lysimeter-A due to the providing of cap liner in anaerobic lysimeter-B and C, played an important role to reduce the percolation of rainwater. The study also reveals that the leachate pollution index (LPI) has decreased in relation to the increasing of elapsed period as well as the LPI for collection system of aerobic lysimeter-A was higher than that of the collection system of anaerobic lysimeter-B and C. Finally, it can be depicted that LPI for lysimeter

  9. Evaluating transition-metal catalysis in gas generation from the Permian Kupferschiefer by hydrous pyrolysis

    Science.gov (United States)

    Lewan, M.D.; Kotarba, M.J.; Wieclaw, D.; Piestrzynski, A.

    2008-01-01

    Transition metals in source rocks have been advocated as catalysts in determining extent, composition, and timing of natural gas generation (Mango, F. D. (1996) Transition metal catalysis in the generation of natural gas. Org. Geochem.24, 977–984). This controversial hypothesis may have important implications concerning gas generation in unconventional shale-gas accumulations. Although experiments have been conducted to test the metal-catalysis hypothesis, their approach and results remain equivocal in evaluating natural assemblages of transition metals and organic matter in shale. The Permian Kupferschiefer of Poland offers an excellent opportunity to test the hypothesis with immature to marginally mature shale rich in both transition metals and organic matter. Twelve subsurface samples containing similar Type-II kerogen with different amounts and types of transition metals were subjected to hydrous pyrolysis at 330° and 355 °C for 72 h. The gases generated in these experiments were quantitatively collected and analyzed for molecular composition and stable isotopes. Expelled immiscible oils, reacted waters, and spent rock were also quantitatively collected. The results show that transition metals have no effect on methane yields or enrichment. δ13C values of generated methane, ethane, propane and butanes show no systematic changes with increasing transition metals. The potential for transition metals to enhance gas generation and oil cracking was examined by looking at the ratio of the generated hydrocarbon gases to generated expelled immiscible oil (i.e., GOR), which showed no systematic change with increasing transition metals. Assuming maximum yields at 355 °C for 72 h and first-order reaction rates, pseudo-rate constants for methane generation at 330 °C were calculated. These rate constants showed no increase with increasing transition metals. The lack of a significant catalytic effect of transition metals on the extent, composition, and timing of

  10. Effects of microbial processes on gas generation under expected WIPP repository conditions: Annual report through 1992

    Energy Technology Data Exchange (ETDEWEB)

    Francis, A.J.; Gillow, J.B.

    1993-09-01

    Microbial processes involved in gas generation from degradation of the organic constituents of transuranic waste under conditions expected at the Waste Isolation Pilot Plant (WIPP) repository are being investigated at Brookhaven National Laboratory. These laboratory studies are part of the Sandia National Laboratories -- WIPP Gas Generation Program. Gas generation due to microbial degradation of representative cellulosic waste was investigated in short-term (< 6 months) and long-term (> 6 months) experiments by incubating representative paper (filter paper, paper towels, and tissue) in WIPP brine under initially aerobic (air) and anaerobic (nitrogen) conditions. Samples from the WIPP surficial environment and underground workings harbor gas-producing halophilic microorganisms, the activities of which were studied in short-term experiments. The microorganisms metabolized a variety of organic compounds including cellulose under aerobic, anaerobic, and denitrifying conditions. In long-term experiments, the effects of added nutrients (trace amounts of ammonium nitrate, phosphate, and yeast extract), no nutrients, and nutrients plus excess nitrate on gas production from cellulose degradation.

  11. Adaptive interpretation of gas well deliverability tests with generating data of the IPR curve

    Science.gov (United States)

    Sergeev, V. L.; Phuong, Nguyen T. H.; Krainov, A. I.

    2017-01-01

    The paper considers topical issues of improving accuracy of estimated parameters given by data obtained from gas well deliverability tests, decreasing test time, and reducing gas emissions into the atmosphere. The aim of the research is to develop the method of adaptive interpretation of gas well deliverability tests with a resulting IPR curve and using a technique of generating data, which allows taking into account additional a priori information, improving accuracy of determining formation pressure and flow coefficients, reducing test time. The present research is based on the previous theoretical and practical findings in the spheres of gas well deliverability tests, systems analysis, system identification, function optimization and linear algebra. To test the method, the authors used the field data of deliverability tests of two wells, run in the Urengoy gas and condensate field, Tyumen Oblast. The authors suggest the method of adaptive interpretation of gas well deliverability tests with the resulting IPR curve and the possibility of generating data of bottomhole pressure and a flow rate at different test stages. The suggested method allows defining the estimates of the formation pressure and flow coefficients, optimal in terms of preassigned measures of quality, and setting the adequate number of test stages in the course of well testing. The case study of IPR curve data processing has indicated that adaptive interpretation provides more accurate estimates on the formation pressure and flow coefficients, as well as reduces the number of test stages.

  12. Waste management in the Irkutsk Region, Siberia, Russia: Environmental assessment of current practice focusing on landfilling

    DEFF Research Database (Denmark)

    Starostina, Vlada; Damgaard, Anders; Rechberger, Helmut

    2014-01-01

    The municipal waste management system of the region of Irkutsk is described and a life cycle assessment (LCA) performed to assess the environmental performance of the system. Annually about 500 000 tons of waste are managed. The waste originates from three sources: household waste (27%), commercial...... waste (23%) and office & institutional waste (44%). Other waste of unknown composition constitutes 6%. Only 3% of the waste is recycled; 97% of the municipal waste is disposed of at the old Alexandrovsky landfill. The environmental impact from the current system is dominated by the landfill, which has...... years, the LCA modelling showed that introduction of a new and modern landfill with gas and leachate collection could improve the performance of the waste management system significantly. Collection of landfill gas and utilization for 30 years for electricity production (gas turbine) would reduce...

  13. Ultrasound imaging of oxidative stress in vivo with chemically-generated gas microbubbles.

    Science.gov (United States)

    Perng, John Kangchun; Lee, Seungjun; Kundu, Kousik; Caskey, Charles F; Knight, Sarah F; Satir, Sarp; Ferrara, Katherine W; Taylor, W Robert; Degertekin, F Levent; Sorescu, Daniel; Murthy, Niren

    2012-09-01

    Ultrasound contrast agents (UCAs) have tremendous potential for in vivo molecular imaging because of their high sensitivity. However, the diagnostic potential of UCAs has been difficult to exploit because current UCAs are based on pre-formed microbubbles, which can only detect cell surface receptors. Here, we demonstrate that chemical reactions that generate gas forming molecules can be used to perform molecular imaging by ultrasound in vivo. This new approach was demonstrated by imaging reactive oxygen species in vivo with allylhydrazine, a liquid compound that is converted into nitrogen and propylene gas after reacting with radical oxidants. We demonstrate that allylhydrazine encapsulated within liposomes can detect a 10 micromolar concentration of radical oxidants by ultrasound, and can image oxidative stress in mice, induced by lipopolysaccharide, using a clinical ultrasound system. We anticipate numerous applications of chemically-generated microbubbles for molecular imaging by ultrasound, given ultrasound's ability to detect small increments above the gas saturation limit, its spatial resolution and widespread clinical use.

  14. Microfluidic generation of uniform water droplets using gas as the continuous phase.

    Science.gov (United States)

    Jiang, Kunqiang; Lu, Annie Xi; Dimitrakopoulos, Panagiotis; DeVoe, Don L; Raghavan, Srinivasa R

    2015-06-15

    Microfluidic schemes for forming uniform aqueous microdroplets usually rely on contacting the aqueous liquid (dispersed phase) with an immiscible oil (continuous phase). Here, we demonstrate that the oil can be substituted with gas (nitrogen or air) while still retaining the ability to generate discrete and uniform aqueous droplets. Our device is a capillary co-flow system, with the inner flow of water getting periodically dispersed into droplets by the external flow of gas. The droplet size and different formation modes can be tuned by varying the liquid and gas flow rates. Importantly, we identify the range of conditions that correspond to the "dripping mode", i.e., where discrete droplets are consistently generated with no satellites. We believe this is a significant development that will be beneficial for chemical and biological applications requiring clean and contaminant-free droplets, including DNA amplification, drug encapsulation, and microfluidic cell culture.

  15. Contribution of N2O to the greenhouse gas balance of first-generation biofuels

    NARCIS (Netherlands)

    Smeets, E.W.M.; Bouwman, A.F.; Stehfest, E.; Vuuren, van P.; Posthuma, A.

    2009-01-01

    n this study, we analyze the impact of fertilizer- and manure-induced N2O emissions due to energy crop production on the reduction of greenhouse gas (GHG) emissions when conventional transportation fuels are replaced by first-generation biofuels (also taking account of other GHG emissions during the

  16. Modeling and experiments on differential pumping in linear plasma generators operating at high gas flows

    NARCIS (Netherlands)

    van Eck, H. J. N.; Koppers, W. R.; van Rooij, G. J.; W. J. Goedheer,; Engeln, R.; D.C. Schram,; Cardozo, N. J. L.; Kleyn, A. W.

    2009-01-01

    The direct simulation Monte Carlo (DSMC) method was used to investigate the efficiency of differential pumping in linear plasma generators operating at high gas flows. Skimmers are used to separate the neutrals from the plasma beam, which is guided from the source to the target by a strong axial mag

  17. Semi-continuous high speed gas analysis of generated vapors of chemical warfare agents

    NARCIS (Netherlands)

    Trap, H.C.; Langenberg, J.P.

    1999-01-01

    A method is presented for the continuous analysis of generated vapors of the nerve agents soman and satin and the blistering agent sulfur mustard. By using a gas sampling valve and a very short (15 cm) column connected to an on-column injector with a 'standard length' column, the system can either

  18. Prediction of gas pressurization and hydrogen generation for shipping hazard analysis : Six unstabilized PU 02 samples

    Energy Technology Data Exchange (ETDEWEB)

    Moody, E. W. (Eddie W.); Veirs, D. K. (Douglas Kirk); Lyman, J. L. (John L.)

    2001-01-01

    Radiolysis of water to form hydrogen gas is a safety concern for safe storage and transport of plutonium-bearing materials. Hydrogen gas is considered a safety hazard if its concentration in the container exceeds five percent hydrogen by volume, DOE Docket No. 00-1 1-9965. Unfortunately, water cannot be entirely avoided in a processing environment and these samples contain a range of water inherently. Thermodynamic, chemical, and radiolysis modeling was used to predict gas generation and changes in gas composition as a function of time within sealed containers containing plutonium bearing materials. The results are used in support of safety analysis for shipping six unstabilized (i.e. uncalcined) samples from Rocky Flats Environmental Technology Sits (RFETS) to the Material Identification and Surveillance (MIS) program at Los Alamos National Lab (LANL). The intent of this work is to establish a time window in which safe shipping can occur.

  19. Metathesis in the generation of low-temperature gas in marine shales.

    Science.gov (United States)

    Mango, Frank D; Jarvie, Daniel M

    2010-01-20

    The recent report of low-temperature catalytic gas from marine shales took on additional significance with the subsequent disclosure of natural gas and low-temperature gas at or near thermodynamic equilibrium in methane, ethane, and propane. It is important because thermal cracking, the presumed source of natural gas, cannot generate these hydrocarbons at equilibrium nor can it bring them to equilibrium over geologic time. The source of equilibrium and the source of natural gas are either the same (generation under equilibrium control) or closely associated. Here we report the catalytic interconversion of hydrocarbons (metathesis) as the source of equilibrium in experiments with Cretaceous Mowry shale at 100 degrees C. Focus was on two metathetic equilibria: methane, ethane, and propane, reported earlier, Q (K = [(C(1))*(C(3))]/[(C(2))(2)]), and between these hydrocarbons and n-butane, Q* (K = [(C(1))*(n-C(4))]/[(C(2))*(C(3))]), reported here for the first time. Two observations stand out. Initial hydrocarbon products are near equilibrium and have maximum average molecular weights (AMW). Over time, products fall from equilibrium and AMW in concert. It is consistent with metathesis splitting olefin intermediates [C(n)] to smaller intermediates (fission) as gas generation creates open catalytic sites ([ ]): [C(n)] + [ ] --> [C(n-m)] + [C(m)]. Fission rates increasing exponentially with olefin molecular weight could contribute to these effects. AMW would fall over time, and selective fission of [C(3)] and [n-C(4)] would draw Q and Q* from equilibrium. The results support metathesis as the source of thermodynamic equilibrium in natural gas.

  20. Metathesis in the generation of low-temperature gas in marine shales

    Directory of Open Access Journals (Sweden)

    Jarvie Daniel M

    2010-01-01

    Full Text Available Abstract The recent report of low-temperature catalytic gas from marine shales took on additional significance with the subsequent disclosure of natural gas and low-temperature gas at or near thermodynamic equilibrium in methane, ethane, and propane. It is important because thermal cracking, the presumed source of natural gas, cannot generate these hydrocarbons at equilibrium nor can it bring them to equilibrium over geologic time. The source of equilibrium and the source of natural gas are either the same (generation under equilibrium control or closely associated. Here we report the catalytic interconversion of hydrocarbons (metathesis as the source of equilibrium in experiments with Cretaceous Mowry shale at 100°C. Focus was on two metathetic equilibria: methane, ethane, and propane, reported earlier, Q (K = [(C1*(C3]/[(C22], and between these hydrocarbons and n-butane, Q* (K = [(C1*(n-C4]/[(C2*(C3], reported here for the first time. Two observations stand out. Initial hydrocarbon products are near equilibrium and have maximum average molecular weights (AMW. Over time, products fall from equilibrium and AMW in concert. It is consistent with metathesis splitting olefin intermediates [Cn] to smaller intermediates (fission as gas generation creates open catalytic sites ([ ]: [Cn] + [ ] → [Cn-m] + [Cm]. Fission rates increasing exponentially with olefin molecular weight could contribute to these effects. AMW would fall over time, and selective fission of [C3] and [n-C4] would draw Q and Q* from equilibrium. The results support metathesis as the source of thermodynamic equilibrium in natural gas.

  1. Airborne monitoring of landfills CH_{4} emissions

    Science.gov (United States)

    Gasbarra, Daniele; Gioli, Beniamino; Carlucci, Pantaleone; Magliulo, Vincenzo; Toscano, Piero; Zaldei, Alessandro

    2017-04-01

    The disposal and treatment of waste produces emissions of greenhouse gases (GHGs), which contribute to global climate change. In particular, large quantities of Methane are released in the breakdown of organic matter in landfills. In this work we present a new payload of the Sky Arrow ERA aircraft and an original methodology to compute methane emissions, based on the atmospheric mass budget approach. The payload is presently being used for intensive measurements in the area known as "Terra dei fuochi". In this area, located between the provinces of Naples and Caserta (Southern Italy), urban waste combined with industrial toxic waste has been illegally dumped in old quarries or buried in the nearby countryside for decades. This led to patchy sources of methane, with several hot spots spread over a heterogeneous land. In this context, the use of aircraft allows for the investigation at the landscape as well as at the regional scale, taking into account all sources, including those of small dimensions. The Sky Arrow ERA is equipped with the Mobile Flux Platform, capable of deriving the 3D wind vector at 50 Hz, while CO2 and water vapor densities are measured by an infrared gas analyzer (Licor 7500). A new configuration of the Licor 7700 open path fast methane gas analyzer was developed, based on enclosing the sensor within a cylinder exposed to the external air in-flow. This set-up allows for fast response measurements, while avoiding external modifications, subjected to restrictions. Ambient methane mixing ratios in excess of 7 ppm were measured during landfills overpasses; performing grid flight plans at different heights, to describe a virtual box enclosing the study area, and applying interpolation procedures, it was possible to reconstruct wind components and scalar concentrations in a 5x5 kilometers domain containing 6 different landfills, with a resolution of 50 m horizontal and 20 m vertical. For each flight the methane mass flows along and across the wind

  2. Energetic utilisation of refuse derived fuels from landfill mining.

    Science.gov (United States)

    Rotheut, Martin; Quicker, Peter

    2017-02-19

    The residence of municipal solid waste within a landfill body results in a significant change of material properties. Experiences with the energetic utilisation of the burnable fractions from formerly landfilled waste are hardly documented, the influence of refuse derived fuels (RDF) from such materials on the performance of modern waste-to-energy plants is not sufficiently described in scientific literature. Therefore this study focuses on the energetic utilisation of refuse derived fuel from landfilled waste, processed in a mechanical waste treatment facility, and the impact of the material on the operation of the incineration plant. Additionally, the possibility of direct combustion of non-pre-treated excavated landfill material has been evaluated in the same facility. First, sampling and analysis of the fuel has been carried out. Based on this, a large-scale combustion experiment was planned and conducted in an industrial waste-to-energy plant. Steam mass flow rate, concentration of harmful substances in the raw gas, as well as total emissions of the facility have been monitored in detail. Furthermore, the influence of the landfilled material on the additive consumption has been determined. The combustion residues (bottom ash) were also sampled and analysed. Based on the evaluation of operating data and analysis of both fuel and residue, suitable thermal treatment approaches for the refuse-derived fuel and the non-pre-treated excavated material have been assessed.

  3. LANDFILL OPERATION FOR CARBON SEQUESTRATION AND MAXIMUM METHANE EMISSION CONTROL

    Energy Technology Data Exchange (ETDEWEB)

    Don Augenstein

    2001-02-01

    The work described in this report, to demonstrate and advance this technology, has used two demonstration-scale cells of size (8000 metric tons [tonnes]), sufficient to replicate many heat and compaction characteristics of larger ''full-scale'' landfills. An enhanced demonstration cell has received moisture supplementation to field capacity. This is the maximum moisture waste can hold while still limiting liquid drainage rate to minimal and safely manageable levels. The enhanced landfill module was compared to a parallel control landfill module receiving no moisture additions. Gas recovery has continued for a period of over 4 years. It is quite encouraging that the enhanced cell methane recovery has been close to 10-fold that experienced with conventional landfills. This is the highest methane recovery rate per unit waste, and thus progress toward stabilization, documented anywhere for such a large waste mass. This high recovery rate is attributed to moisture, and elevated temperature attained inexpensively during startup. Economic analyses performed under Phase I of this NETL contract indicate ''greenhouse cost effectiveness'' to be excellent. Other benefits include substantial waste volume loss (over 30%) which translates to extended landfill life. Other environmental benefits include rapidly improved quality and stabilization (lowered pollutant levels) in liquid leachate which drains from the waste.

  4. Generation and Migration of Natural Gas in Miocene Strata, Offshore Southeastern Korea

    Science.gov (United States)

    Son, Byeong-Kook

    2016-04-01

    Natural gas and condensate are produced from Miocene strata of the Tertiary marine basin, called Ulleung Basin, which is located offshore southeastern Korea. Petroleum system in the basin has not been fully understood, because effective source rocks have not been identified in the area. However, 1-D petroleum system modelling and isotope data indicate that the source rock of the natural gas and condensate might be present at deeper strata than 5,000 m in the basin. In addition, the analysis of diamondoids in the condensate shows that the gas was transformed from type II kerogen. Based on this source rock information and other geological data, 2-D petroleum system modelling was conducted on two cross sections in the southwestern margin of the basin. The 2-D models show two phase generation and migration, which are caused by the geometry of source bed and the maturity level of each pod of the bed. In addition, the accumulation of hydrocarbon is constrained greatly by the timing of development of the regional seal. The first generation and migration of oil and gas begins with a high rate of sedimentation at a deeply and early buried pod of the source bed at 15 Ma. The hydrocarbon, however, migrates upward and diffuses toward the surface. The second generation and migration occurs at around 11 Ma from the other pod of the source bed. This hydrocarbon migrates updip toward anticlines and accumulates into the traps of anticlines. On the other hand, the model shows that the generation and migration is dominated by gas, rather than oil. This model indicates that the accumulation of hydrocarbon can be completed only by the proper and sophisticated combination of the geological elements and the timing of hydrocarbon migration in time and space. This 2-D feature of generation and migration is supported by additional 1-D models of two pseudo-wells drilled on the 2-D section.

  5. Depo Gazı Enerji Üretim Tesisi Baca Gazı Atık Isısının Seralarda Değerlendirilmesi: İstanbul Örneği / Utilization of Waste Heat in Energy Production Plant from Landfill Gas at Greenhouses – Case Study in Istanbul

    Directory of Open Access Journals (Sweden)

    Volkan Enç

    2012-12-01

    yapılacaktır. Odayeri Düzenli Depolama Sahasında uygun alan tespiti ve yetiştirilecek ürün tespiti yapıldıktan sonra sera kurulumuna geçilmiştir. Seralarda yetiştirilecek ürünler için uygun koşulların sağlanması için iklimlendirme, sulama ve gübreleme sistemi dizayn edilmiş ve sistemlerin tamamı tam otomasyonlu yapılmıştır. Depo gazı Enerji Üretim Tesisinde depo gazı yakılarak elektrik enerjisi üretiminde kullanılmakta, çok yüksek sıcaklıkta baca gazı atmosfere verilmektedir. Bu gazın değerlendirilmesinin önemli ekonomik faydalar sağlayacağı tespit edilmiştir. Seracılık, ülkemizde ve dünyada önemli bir tarım faaliyeti olmakta ve bu sürecin gelişimde ısıtma maliyeti önemli bir kısıt olarak karşımıza çıkmaktadır. Ülkemizde ısıtmaya bağlı olarak seracılık sıcak iklim bölgelerinde ve jeotermal enerjiye sahip bölgelerde yapılabilmektedir. Kış ısıtması genel itibari ile yetersiz kalmakta ya da hiç yapılamamaktadır. Proje sonucunda ortaya konan sistem, atık yönetiminin önemli sıkıntılarına çözümler getirmektedir. Belediyeler ve çok farklı sektörlerden işletmeler için problem teşkil eden atıl durumdaki depolama sahaları, değerlendirilemeyen atık ısı, seracılık alan sıkıntısı, sera ısıtma giderleri ve işsizlik gibi konular proje sayesinde bütüncül bir şekilde ele alınmıştır. Utilization of Waste Heat in Energy Production Plant from Landfill Gas at Greenhouses – Case Study in Istanbul After the lifetime of regular landfill ended, the rest of useful field becomes very limited. This areas used for green field are inactive in terms of environmental respect. The usage of the storage fields is critical for Istanbul where the empty lands are limited. Methane comes out from landfill and is controlled with different methods. Electricity is generated after the process of collecting, transferring, and burning of methane gas. Consuming methane gas in the plants leads

  6. Onsite survey on the mechanism of passive aeration and air flow path in a semi-aerobic landfill.

    Science.gov (United States)

    Matsuto, Toshihiko; Zhang, Xin; Matsuo, Takayuki; Yamada, Shuhei

    2015-02-01

    The semi-aerobic landfill is a widely accepted landfill concept in Japan because it promotes stabilization of leachates and waste via passive aeration without using any type of mechanical equipment. Ambient air is thought to be supplied to the landfill through a perforated pipe network made of leachate collection pipe laid along the bottom and a vertically erected gas vent. However, its underlying air flow path and driving forces are unclear because empirical data from real-world landfills is inadequate. The objective of this study is to establish scientific evidence about the aeration mechanisms and air flow path by an on-site survey of a full-scale, semi-aerobic landfill. First, all passive vents located in the landfill were monitored with respect to temperature level and gas velocity in different seasons. We found a linear correlation between the outflow rate and gas temperature, suggesting that air flow is driven by a buoyancy force caused by the temperature difference between waste in the landfill and the ambient temperature. Some vents located near the landfill bottom acted as air inflow vents. Second, we conducted a tracer test to determine the air flow path between two vents, by injecting tracer gas from an air sucking vent. The resulting slowly increasing gas concentration at the neighboring vent suggested that fresh air flow passes through the waste layer toward the gas vents from leachate collection pipes, as well as directly flowing through the pipe network. Third, we monitored the temperature of gas flowing out of a vent at night. Since the temperature drop of the gas was much smaller than that of the environment, the air collected at the gas vents was estimated to flow mostly through the waste layer, i.e., the semi-aerobic landfill has considerable aeration ability under the appropriate conditions.

  7. A discussion on the upper limit of maturity for gas generation by marine kerogens and the utmost of gas generative potential: Taking the study on the Tarim Basin as an example

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The experimental data yielded by Rock-Eval pyrolysis, kerogen atomic H/C, Py-GC and gold-tube sealing thermal simulation on the marine Cambrian-Ordovician source rock from the Tarim Basin revealed that the upper limit of maturity for natural gas generation or the "deadline of gas generation" for marine types Ⅰ and Ⅱ kerogens is equal to 3.0% of vitrinite reflectance (Ro); while the "deadline of gas generation" for type Ⅲ kerogens typically like coals is as high as 10% Ro. Thus, different organic matter has obviously different utmost maturities for gas generation. The mass-balance calculation by kerogen elements showed that when Ro>1.5%, the utmost amount of gas generation for the marine type Ⅱ kerogen is less than 185 m3/t TOC, accounting for less than 30% of its total hydrocarbon generative potential; when Ro>2.0%, it becomes 110 m3/t TOC, less than 20% of the total hydrocarbon generative potential. The amount of the gas generative potential obtained by Rock-Eval is only around one tenth of the calculated value by the mass balance of kerogen elements at the same thermal evolutionary stage,while those by Py-GC and gold-tube sealing simulation are intervenient between the above two. The utmost of gas generative potential at the over 1.3% Ro stage is around 60-90 m3/t TOC, therefore, the amount of gas generation obtained by Rock-Eval is the minimum of gas generative potential, while that by the mass-balance calculation of kerogen elements is the maximum that the actual amount of gas generation should not exceed.

  8. Three annual flue gas desulfurization gypsum applications on macronutrient and micronutrient losses in runoff from bermudagrass fertilized with poultry litter

    Science.gov (United States)

    Considerable amounts of flue gas desulfurization (FGD) gypsum are being produced as a by-product of generating electricity. As a result, beneficial reuse of this by-product is being sought to reduce landfilling and its associated cost. The use of this byproduct as a low-cost soil amendment for suppl...

  9. Atmospheric dc discharges with miniature gas flow as microplasma generation method

    Energy Technology Data Exchange (ETDEWEB)

    Yokoyama, Takuma; Hamada, Shuhei; Ibuka, Shinji; Yasuoka, Koichi; Ishii, Shozo [Department of Electrical and Electronic Engineering, Tokyo Institute of Technology, Tokyo 152-8552 (Japan)

    2005-06-07

    An atmospheric microplasma is generated by direct-current (dc) discharge in air with a miniature gas flow through a nozzle, which limits plasma volume. Two discharge modes appear in a nozzle-to-mesh electrode system with helium or argon. One is a repetitive pulsed discharge with a current of 10-30 mA and a short pulse width. The fast pulsed current is powered by electric charges stored in the parasitic capacitance, which depends on the spatial arrangement of the electrodes and the power leads. The pulsed discharge makes it possible to develop a discharge scheme for microplasma generation without a high-voltage pulse generator. The other is a sustained dc discharge, which develops with increasing applied voltage. In the case of helium, a glow discharge configuration is observed with a positive column and a layered structure near the cathode. The length of the positive column is affected by electrode separation and gas flow rate.

  10. Landfill aeration for emission control before and during landfill mining.

    Science.gov (United States)

    Raga, Roberto; Cossu, Raffaello; Heerenklage, Joern; Pivato, Alberto; Ritzkowski, Marco

    2015-12-01

    The landfill of Modena, in northern Italy, is now crossed by the new high velocity railway line connecting Milan and Bologna. Waste was completely removed from a part of the landfill and a trench for the train line was built. With the aim of facilitating excavation and further disposal of the material extracted, suitable measures were defined. In order to prevent undesired emissions into the excavation area, the aerobic in situ stabilisation by means of the Airflow technology took place before and during the Landfill Mining. Specific project features involved the pneumatic leachate extraction from the aeration wells (to keep the leachate table low inside the landfill and increase the volume of waste available for air migration) and the controlled moisture addition into a limited zone, for a preliminary evaluation of the effects on process enhancement. Waste and leachate were periodically sampled in the landfill during the aeration before the excavation, for quality assessment over time; the evolution of biogas composition in the landfill body and in the extraction system for different plant set-ups during the project was monitored, with specific focus on uncontrolled migration into the excavation area. Waste biological stability significantly increased during the aeration (waste respiration index dropped to 33% of the initial value after six months). Leachate head decreased from 4 to 1.5m; leachate recirculation tests proved the beneficial effects of moisture addition on temperature control, without hampering waste aerobization. Proper management of the aeration plant enabled the minimization of uncontrolled biogas emissions into the excavation area.

  11. Batch test assessment of waste-to-energy combustion residues impacts on precipitate formation in landfill leachate collection systems.

    Science.gov (United States)

    Cardoso, Antonio J; Levine, Audrey D; Rhea, Lisa R

    2008-01-01

    Disposal practices for bottom ash and fly ash from waste-to-energy (WTE) facilities include emplacement in ash monofills or co-disposal with municipal solid waste (MSW) and residues from water and wastewater treatment facilities. In some cases, WTE residues are used as daily cover in landfills that receive MSW. A recurring problem in many landfills is the development of calcium-based precipitates in leachate collection systems. Although MSW contains varying levels of calcium, WTE residues and treatment plant sludges have the potential to contribute concentrated sources of leachable minerals into landfill leachates. This study was conducted to evaluate the leachability of calcium and other minerals from residues generated by WTE combustion using residues obtained from three WTE facilities in Florida (two mass-burn and one refuse-derived fuel). Leaching potential was quantified as a function of contact time and liquid-to-solid ratios with batch tests and longer-term leaching tests using laboratory lysimeters to simulate an ash monofill containing fly ash and bottom ash. The leachate generated as a result of these tests had total dissolved solid (TDS) levels ranging from 5 to 320 mg TDS/g ash. Calcium was a major contributor to the TDS values, contributing from 20 to 105 g calcium/kg ash. Fly ash was a major contributor of leachable calcium. Precipitate formation in leachates from WTE combustion residues could be induced by adding mineral acids or through gas dissolution (carbon dioxide or air). Stabilization of residual calcium in fly ashes that are landfilled and/or the use of less leachable neutralization reagents during processing of acidic gases from WTE facilities could help to decrease the calcium levels in leachates and help to prevent precipitate formation in leachate collection systems.

  12. Landfill aeration in the framework of a reclamation project in Northern Italy.

    Science.gov (United States)

    Raga, Roberto; Cossu, Raffaello

    2014-03-01

    In situ aeration by means of the Airflow technology was proposed for landfill conditioning before landfill mining in the framework of a reclamation project in Northern Italy. A 1-year aeration project was carried out on part of the landfill with the objective of evaluating the effectiveness of the Airflow technology for landfill aerobization, the evolution of waste biological stability during aeration and the effects on leachate and biogas quality and emissions. The main outcomes of the 1-year aeration project are presented in the paper. The beneficial effect of the aeration on waste biological stability was clear (63% reduction of the respiration index); however, the effectiveness of aeration on the lower part of the landfill is questionable, due to the limited potential for air migration into the leachate saturated layers. During the 1-year in situ aeration project approx. 275 MgC were discharged from the landfill body with the extracted gas, corresponding to 4.6 gC/kgDM. However, due to the presence of anaerobic niches in the aerated landfill, approx. 46% of this amount was extracted as CH4, which is higher than reported in other aeration projects. The O2 conversion quota was lower than reported in other similar projects, mainly due to the higher air flow rates applied. The results obtained enabled valuable recommendations to be made for the subsequent application of the Airflow technology to the whole landfill.

  13. Bio-tarp alternative daily cover prototypes for methane oxidation atop open landfill cells.

    Science.gov (United States)

    Adams, Bryn L; Besnard, Fabien; Bogner, Jean; Hilger, Helene

    2011-05-01

    Final landfill covers are highly engineered to prevent methane release into the atmosphere. However, methane production begins soon after waste placement and is an unaddressed source of emissions. The methane oxidation capacity of methanotrophs embedded in a "bio-tarp" was investigated as a means to mitigate methane release from open landfill cells. The bio-tarp would also serve as an alternative daily cover during routine landfill operation. Evaluations of nine synthetic geotextiles identified two that would likely be suitable bio-tarp components. Pilot tarp prototypes were tested in continuous flow systems simulating landfill gas conditions. Multilayered bio-tarp prototypes consisting of alternating layers of the two geotextiles were found to remove 16% of the methane flowing through the bio-tarp. The addition of landfill cover soil, compost, or shale amendments to the bio-tarp increased the methane removal up to 32%. With evidence of methane removal in a laboratory bioreactor, prototypes were evaluated at a local landfill using flux chambers installed atop intermediate cover at a landfill. The multilayered bio-tarp and amended bio-tarp configurations were all found to decrease landfill methane flux; however, the performance efficacy of bio-tarps was not significantly different from controls without methanotrophs. Because highly variable methane fluxes at the field site likely confounded the test results, repeat field testing is recommended under more controlled flux conditions.

  14. Minimizing N2O fluxes from full-scale municipal solid waste landfill with properly selected cover soil

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Municipal solid waste landfills emit nitrous oxide (N2O) gas. Assuming that the soil cover is the primary N2O source from landfills,this study tested, during a four-year project, the hypothesis that the proper use of chosen soils with fine texture minimizes N2O emissions. A full-scale sanitary landfill, a full-scale bioreactor landfill and a cell planted with Nerium indicum or Festuca arundinacea Schreb, at the Hangzhou Tianziling landfill in Hangzhou City were the test sites. The N2O emission rates from all test sites were considerably lower than those reported in the published reports. Specifically, the N2O emission rate was dependent on soil water content and nitrate concentrations in the cover soil. The effects of leachate recirculation and irrigation were minimal. Properly chosen cover soils applied to the landfills reduced N2O flux.

  15. Ultraviolet Light Generation in Gas-Filled Kagome Photonic Crystal Fiber

    Science.gov (United States)

    Rodrigues, Sílvia M. G.; Facão, Margarida; Ferreira, Mário F. S.

    2015-03-01

    Kagome hollow-core photonic crystal fibers were found to be ideal for the occurrence of ultrafast non-linear optics. This article reports the optimal conditions for the generation of ultraviolet light using a gas filled kagome hollow-core-photonic crystal fiber. It is shown that by changing the pressure of the gas and the input pulse characteristics, the efficiency of conversion and quality of ultraviolet light can be improved, as well as tuning its central frequency. Results suggest that a highly coherent and tunable ultraviolet light source can be constructed, which can find numerous applications.

  16. Moisture effects on greenhouse gases generation in nitrifying gas-phase compost biofilters.

    Science.gov (United States)

    Maia, Guilherme D N; Day, George B; Gates, Richard S; Taraba, Joseph L; Coyne, Mark S

    2012-06-01

    Gas-phase compost biofilters are extensively used in concentrated animal feeding operations to remove odors and, in some cases, ammonia from air sources. The expected biochemical pathway for these predominantly aerobic systems is nitrification. However, non-uniform media with low oxygen levels can shift biofilter microbial pathways to denitrification, a source of greenhouse gases. Several factors contribute to the formation of anoxic/anaerobic zones: media aging, media and particle structure, air velocity distribution, compaction, biofilm thickness, and moisture content (MC) distribution. The present work studies the effects of media moisture conditions on ammonia (NH(3)) removal and greenhouse gas generation (nitrous oxide, N(2)O and methane, CH(4)) for gas-phase compost biofilters subject to a 100-day controlled drying process. Continuous recordings were made for the three gases and water vapor (2.21-h sampling cycle, each cycle consisted of three gas species, and water vapor, for a total of 10,050 data points). Media moisture conditions were classified into three corresponding media drying rate (DR) stages: Constant DR (wetter media), falling DR, and stable-dry system. The first-half of the constant DR period (0-750 h; MC=65-52%, w.b.) facilitated high NH(3) removal rates, but higher N(2)O generation and no CH(4) generation. At the drier stages of the constant DR (750-950 h; MC=52-48%, w.b.) NH(3) removal remained high but N(2)O net generation decreased to near zero. In the falling DR stage (1200-1480 h; MC=44-13%) N(2)O generation decreased, CH(4) increased, and NH(3) was no longer removed. No ammonia removal or greenhouse gas generation was observed in the stable-dry system (1500-2500 h; MC=13%). These results indicate that media should remain toward the drier region of the constant DR (in close proximity to the falling DR stage; MC=50%, approx.), to maintain high levels of NH(3) removal, reduced levels of N(2)O generation, and nullify levels of CH(4

  17. Life Cycle Greenhouse Gas Emissions from Electricity Generation: A Comparative Analysis of Australian Energy Sources

    Directory of Open Access Journals (Sweden)

    Robert G. Hynes

    2012-03-01

    Full Text Available Electricity generation is one of the major contributors to global greenhouse gas emissions. Transitioning the World’s energy economy to a lower carbon future will require significant investment in a variety of cleaner technologies, including renewables and nuclear power. In the short term, improving the efficiency of fossil fuel combustion in energy generation can provide an important contribution. Availability of life cycle GHG intensity data will allow decision-makers to move away from overly simplistic assertions about the relative merits of certain fuels, and focus on the complete picture, especially the critical roles of technology selection and application of best practice. This analysis compares the life-cycle greenhouse gas (GHG intensities per megawatt-hour (MWh of electricity produced for a range of Australian and other energy sources, including coal, conventional liquefied natural gas (LNG, coal seam gas LNG, nuclear and renewables, for the Australian export market. When Australian fossil fuels are exported to China, life cycle greenhouse gas emission intensity in electricity production depends to a significant degree on the technology used in combustion. LNG in general is less GHG intensive than black coal, but the gap is smaller for gas combusted in open cycle gas turbine plant (OCGT and for LNG derived from coal seam gas (CSG. On average, conventional LNG burned in a conventional OCGT plant is approximately 38% less GHG intensive over its life cycle than black coal burned in a sub-critical plant, per MWh of electricity produced. However, if OCGT LNG combustion is compared to the most efficient new ultra-supercritical coal power, the GHG intensity gap narrows considerably. Coal seam gas LNG is approximately 13–20% more GHG intensive across its life cycle, on a like-for like basis, than conventional LNG. Upstream fugitive emissions from CSG (assuming best practice gas extraction techniques do not materially alter the life cycle

  18. Numerical study on the generation of a planar supersonic gas-jet

    Energy Technology Data Exchange (ETDEWEB)

    Putignano, M., E-mail: massimilianoputignano@quasar-group.org [Cockcroft Institute, Daresbury Laboratory, Warrington (United Kingdom); University of Liverpool, Liverpool (United Kingdom); Welsch, C.P. [University of Liverpool, Liverpool (United Kingdom)

    2012-03-01

    Planar supersonic gas-jets are valuable tools for different applications such as state of the art molecular spectroscopy and accelerator beam instrumentation; however, the details of their expansion and generation have not yet been analyzed extensively, despite numerous studies addressing these same questions for the simpler case of the axis-symmetric jet. In this paper, we investigate numerically the generation and evolution of planar supersonic gas-jets, extending the optimization studies done for axis-symmetric jets and focusing in particular on applications in accelerator beam instrumentation. We introduce a set of dedicated quality factors and use them to investigate the effects of changes to the geometry and thermodynamic state of the nozzle-skimmer system used to generate the planar jet. This analysis leads to an innovative, optimized nozzle-skimmer system design, which features advantages in terms of planar jet quality when compared to traditional setups. The proposed design also gives the possibility to modify, by variation of the thermodynamic quantities alone, the gas-jet characteristics in a wide range, including jet splitting and local density modulation. Density profiles of the generated jets are plotted for different parameter set.

  19. Effect of enzyme additions on methane production and lignin degradation of landfilled sample of municipal solid waste.

    Science.gov (United States)

    Jayasinghe, P A; Hettiaratchi, J P A; Mehrotra, A K; Kumar, Sunil

    2011-04-01

    Operation of waste cells as landfill bioreactors with leachate recirculation is known to accelerate waste degradation and landfill gas generation. However, waste degradation rates in landfill bioreactors decrease with time, with the accumulation of difficult to degrade materials, such as lignin-rich waste. Although, potential exists to modify the leachate quality to promote further degradation of such waste, very little information is available in literature. The objective of this study was to determine the viability of augmenting leachate with enzymes to increase the rate of degradation of lignin-rich waste materials. Among the enzymes evaluated MnP enzyme showed the best performance in terms of methane yield and substrate (lignin) utilization. Methane production of 200 mL CH(4)/g VS was observed for the MnP amended reactor as compared to 5.7 mL CH(4)/g VS for the control reactor. The lignin reduction in the MnP amended reactor and control reactor was 68.4% and 6.2%, respectively.

  20. Variance Analysis of Wind and Natural Gas Generation under Different Market Structures: Some Observations

    Energy Technology Data Exchange (ETDEWEB)

    Bush, B.; Jenkin, T.; Lipowicz, D.; Arent, D. J.; Cooke, R.

    2012-01-01

    Does large scale penetration of renewable generation such as wind and solar power pose economic and operational burdens on the electricity system? A number of studies have pointed to the potential benefits of renewable generation as a hedge against the volatility and potential escalation of fossil fuel prices. Research also suggests that the lack of correlation of renewable energy costs with fossil fuel prices means that adding large amounts of wind or solar generation may also reduce the volatility of system-wide electricity costs. Such variance reduction of system costs may be of significant value to consumers due to risk aversion. The analysis in this report recognizes that the potential value of risk mitigation associated with wind generation and natural gas generation may depend on whether one considers the consumer's perspective or the investor's perspective and whether the market is regulated or deregulated. We analyze the risk and return trade-offs for wind and natural gas generation for deregulated markets based on hourly prices and load over a 10-year period using historical data in the PJM Interconnection (PJM) from 1999 to 2008. Similar analysis is then simulated and evaluated for regulated markets under certain assumptions.

  1. Analysis of Precooling Injection Transient of Steam Generator for High Temperature Gas Cooled Reactor

    Directory of Open Access Journals (Sweden)

    Yan Wang

    2017-01-01

    Full Text Available After a postulated design basis accident leads high temperature gas cooled reactor to emergency shutdown, steam generator still remains with high temperature level and needs to be cooled down by a precooling before reactor restarts with clearing of fault. For the large difference of coolant temperature between inlet and outlet of steam generator in normal operation, the temperature distribution on the components of steam generator is very complicated. Therefore, the temperature descending rate of the components in steam generator needs to be limited to avoid the potential damage during the precooling stage. In this paper, a pebble-bed high temperature gas cooled reactor is modeled by thermal-hydraulic system analysis code and several postulated precooling injection transients are simulated and compared to evaluate their effects, which will provide support for the precooling design. The analysis results show that enough precooling injection is necessary to satisfy the precooling requirements, and larger mass flow rate of precooling water injection will accelerate the precooling process. The temperature decrease of steam generator is related to the precooling injection scenarios, and the maximal mass flow rate of the precooling injection should be limited to avoid the excessively quick temperature change of the structures in steam generator.

  2. PRACTICE REVIEW OF FIVE BIOREACTOR/RECIRCULATION LANDFILLS

    Science.gov (United States)

    Six bioreactor landfills were analyzed to provide a perspective of current practice and technical issues that differentiate bioreactor landfills from conventional landfills. Five of the bioreactor landfills were anaerobic and one was aerated. In one case, nearly identical cells e...

  3. Energy utilization from landfill biogas; Aproveitamento energetico do biogas de aterros sanitarios

    Energy Technology Data Exchange (ETDEWEB)

    Candiani, Giovano [Universidade Federal do ABC, Santo Andre, SP (Brazil). Programa de Pos-Graduacao em Energia; Hoffmann, Gustavo; Silva, Elissandro Rocha da; Moreira, Joao M.L.; Tomioka, Jorge

    2008-07-01

    Landfills for solid waste disposal are used in Brazil and in most of countries in the world. The organic part of the solid wastes produces gas out of the decomposition of its organic content. This gas, named biogas and mostly made of carbon dioxide and methane, may be collected and used as an energy source due the methane presence. In this work we analyze the possible energy utilization of landfill biogas in Brazil in which the organic content of the solid waste is about 60%. The use of biogas as energy source can reduce the greenhouse gas emissions and improve the sanitation conditions of landfills. Moreover, it allows financial gains through selling of energy and carbon credits. In order to make possible the biogas utilization it is necessary to recognize the differences among the many landfills which exist in the country. There are the large and small landfills. The large ones usually have good instrumentation and gas exhaustion systems while the small ones have passive exhaustion systems and very few field instrumentation. The small landfills need to improve their instrumentation system and to incorporate exhaustion systems. (author)

  4. Landfills as sources of polyfluorinated compounds, polybrominated diphenyl ethers and musk fragrances to ambient air

    Science.gov (United States)

    Weinberg, Ingo; Dreyer, Annekatrin; Ebinghaus, Ralf

    2011-02-01

    In order to investigate landfills as sources of polyfluorinated compounds (PFCs), polybrominated diphenyl ethers (PBDEs) and synthetic musk fragrances to the atmosphere, air samples were simultaneously taken at two landfills (one active and one closed) and two reference sites using high volume air samplers. Contaminants were accumulated on glass fiber filters (particle phase) and PUF/XAD-2/PUF cartridges (gas phase), extracted by methyl-tert butyl ether/acetone (neutral PFCs), methanol (ionic PFCs) or hexane/acetone (PBDEs, musk fragrances), and detected by GC-MS (neutral PFCs, PBDEs, musk fragrances) or HPLC-MS/MS (ionic PFCs). Total concentrations ranged from 84 to 706 pg m -3 (volatile PFCs, gas phase), from gas + particle phase) and from 1 to 11 pg m -3 (PBDEs, gas + particle phase). Observed sum concentrations of PFCs and synthetic musk fragrances and partly PBDE concentrations were elevated at landfill sites compared to corresponding reference sites. Concentrations determined at the active landfill were higher than those of the inactive landfill. Overall, landfills can be regarded as a source of synthetic musk fragrances, several PFCs and potentially of PBDEs to ambient air.

  5. Experimental check of possibility of research of repeated inclusion of the open gas generator in the water environment

    Directory of Open Access Journals (Sweden)

    Goldaev Sergey

    2017-01-01

    Full Text Available Experimental study of repeated burning interruption with the subsequent ignition in the water environment for bibasic firm fuel as a part of a model open solid propellant gas generator is presented. Video filming of burning zone mobile localizer providing process of repeated inclusion of a gas generator are given. Some parameters of the processes proceeding in these conditions are defined

  6. A framework for assessment and characterisation of municipal solid waste landfill leachate: an application to the Turbhe landfill, Navi Mumbai, India.

    Science.gov (United States)

    Mishra, Harshit; Rathod, Merwan; Karmakar, Subhankar; Kumar, Rakesh

    2016-06-01

    Rapid industrialisation, growing population and changing lifestyles are the root causes for the generation of huge amounts of solid waste in developing countries. In India, disposal of municipal solid waste (MSW) through open dumping is the most common waste disposal method. Unfortunately, leachate generation from landfill is high due to the prolonged and prominent monsoon season in India. As leachate generation rate is high in most of the tropical countries, long-term and extensive monitoring efforts are expected to evaluate actual environmental pollution potential due to leachate contamination. However, the leachate characterisation involves a comprehensive process, which has numerous shortcomings and uncertainties possibly due to the complex nature of landfilling process, heterogeneous waste characteristics, widely varying hydrologic conditions and selection of analytes. In order to develop a sustainable MSW management strategy for protecting the surface and ground water resources, particularly from MSW landfill leachate contamination, assessment and characterisation of leachate are necessary. Numerous studies have been conducted in the past to characterise leachate quality from various municipal landfills; unfortunately, none of these propose a framework or protocol. The present study proposes a generic framework for municipal landfill leachate assessment and characterisation. The proposed framework can be applied to design any type of landfill leachate quality monitoring programme and also to facilitate improved leachate treatment activities. A landfill site located at Turbhe, Navi Mumbai, India, which had not been investigated earlier, has been selected as a case study. The proposed framework has been demonstrated on the Turbhe landfill site which is a comparatively new and the only sanitary landfill in Navi Mumbai.

  7. Potential application of biocover soils to landfills for mitigating toluene emission.

    Science.gov (United States)

    Su, Yao; Pei, Junshen; Tian, Baohu; Fan, Fengxi; Tang, Mengling; Li, Wei; He, Ruo

    2015-12-15

    Biocover soils have been demonstrated to be a good alternative cover material to mitigate CH4 emission from landfills. To evaluate the potential of biocover soil in mitigating emissions of non-methane volatile organic compounds (NMVOCs) from landfills, simulated cover soil columns with the influx of toluene (chosen as typical of NMVOCs) concentrations of 102-1336 mg m(-3) in the presence or absence of the major landfill gas components (i.e., CH4 and CO2) were conducted in this study. In the two experimental materials (waste biocover soils (WBS) and landfill cover soils (LCS)), higher toluene reduction was observed in WBS with respect to LCS. After the introduction of landfill gas, an increase of microbial diversity and relative abundance of toluene-degrading bacteria and methanotrophs occurred in WBS. To illustrate the role of toluene-degrading activity in mitigating toluene emissions through landfill covers, an analytical model was developed by incorporating the steady-state vapor transport with the first-order kinetics of aerobic biodegradation limited by O2 availability. This study demonstrated that biocover soils have great potential in applying to landfills for mitigating toluene emission to the atmosphere.

  8. Thermal-maturity limit for primary thermogenic-gas generation from humic coals as determined by hydrous pyrolysis

    Science.gov (United States)

    Lewan, Michael; Kotarba, M.J.

    2014-01-01

    Hydrous-pyrolysis experiments at 360°C (680°F) for 72 h were conducted on 53 humic coals representing ranks from lignite through anthracite to determine the upper maturity limit for hydrocarbon-gas generation from their kerogen and associated bitumen (i.e., primary gas generation). These experimental conditions are below those needed for oil cracking to ensure that generated gas was not derived from the decomposition of expelled oil generated from some of the coals (i.e., secondary gas generation). Experimental results showed that generation of hydrocarbon gas ends before a vitrinite reflectance of 2.0%. This reflectance is equivalent to Rock-Eval maximum-yield temperature and hydrogen indices (HIs) of 555°C (1031°F) and 35 mg/g total organic carbon (TOC), respectively. At these maturity levels, essentially no soluble bitumen is present in the coals before or after hydrous pyrolysis. The equivalent kerogen atomic H/C ratio is 0.50 at the primary gas-generation limit and indicates that no alkyl moieties are remaining to source hydrocarbon gases. The convergence of atomic H/C ratios of type-II and -I kerogen to this same value at a reflectance of indicates that the primary gas-generation limits for humic coal and type-III kerogen also apply to oil-prone kerogen. Although gas generation from source rocks does not exceed vitrinite reflectance values greater than , trapped hydrocarbon gases can remain stable at higher reflectance values. Distinguishing trapped gas from generated gas in hydrous-pyrolysis experiments is readily determined by of the hydrocarbon gases when a -depleted water is used in the experiments. Water serves as a source of hydrogen in hydrous pyrolysis and, as a result, the use of -depleted water is reflected in the generated gases but not pre-existing trapped gases.

  9. Monitoring fugitive CH4 and CO2 emissions from a closed landfill at Tenerife, Canary Islands

    Science.gov (United States)

    Asensio-Ramos, María; Tompkins, Mitchell R. K.; Turtle, Lara A. K.; García-Merino, Marta; Amonte, Cecilia; Rodrígez, Fátima; Padrón, Eleazar; Melián, Gladys V.; Padilla, Germán; Barrancos, José; Pérez, Nemesio M.

    2017-04-01

    Solid waste must be managed systematically to ensure environmental best practices. One of the ways to manage this huge problem is to systematic dispose waste materials in locations such as landfills. However, landfills could face possible threats to the environment such as groundwater pollution and the release of landfill gases (CH4, volatile organic compounds, etc.) to the atmosphere. These structures should be carefully filled, monitored and maintained while they are active and for up to 30 years after they are closed. Even after years of being closed, a systematically amount of landfill gas could be released to the atmosphere through its surface in a diffuse and fugitive form. During the period 1999-2016, we have studied the spatial-temporal distribution of the surface fugitive emission of CO2 and CH4 into the atmosphere in a cell in the Arico's municipal landfill (0.3 km2) at Tenerife, Canary Islands, Spain. This cell was operative until 2004, when it was filled and closed. Monitoring these diffuse landfill emissions provides information of how the closed landfill is degassing. To do so, we have performed 9 gas emission surveys during the period 1999-2016. Surface landfill CO2 efflux measurements were carried out at around 450 sampling site by means of a portable non-dispersive infrared spectrophotometer (NDIR) model LICOR Li800 following the accumulation chamber method. Landfill gases taken in the chamber were analyzed using a double channel VARIAN 4900 micro-GC. CH4 efflux measurements were computed combining CO2 efflux measurements and CH4/CO2 ratio in the landfill's surface gas. To quantify the total CH4 emission, CH4 efflux contour map was constructed using sequential Gaussian simulation (sGs) as interpolation method. In general, a decrease in the CO2 emission is observed since the cell was closed (2004) to the present. The total CO2 and CH4 diffuse emissions estimated in the 2016 survey were 4.54 ± 0.14 t d-1 and 268.65 ± 17.99 t d-1, respectively

  10. Accounting for fuel price risk when comparing renewable togas-fired generation: the role of forward natural gas prices

    Energy Technology Data Exchange (ETDEWEB)

    Bolinger, Mark; Wiser, Ryan; Golove, William

    2004-07-17

    Unlike natural gas-fired generation, renewable generation (e.g., from wind, solar, and geothermal power) is largely immune to fuel price risk. If ratepayers are rational and value long-term price stability, then--contrary to common practice--any comparison of the levelized cost of renewable to gas-fired generation should be based on a hedged gas price input, rather than an uncertain gas price forecast. This paper compares natural gas prices that can be locked in through futures, swaps, and physical supply contracts to contemporaneous long-term forecasts of spot gas prices. We find that from 2000-2003, forward gas prices for terms of 2-10 years have been considerably higher than most contemporaneous long-term gas price forecasts. This difference is striking, and implies that comparisons between renewable and gas-fired generation based on these forecasts over this period have arguably yielded results that are biased in favor of gas-fired generation.

  11. Evaluation of respiration in compost landfill biocovers intended for methane oxidation

    DEFF Research Database (Denmark)

    Scheutz, Charlotte; Pedicone, Alessio; Pedersen, Gitte Bukh

    2011-01-01

    will compete for O2 with other aerobic microorganisms. If the compost is not mature, a significant portion of the O2 diffusing into the compost layer will be consumed by non-methanotrophs, thereby limiting CH4 oxidation. The results of this study however also suggest that the consumption of O2 in the compost......A low-cost alternative approach to reduce landfill gas (LFG) emissions is to integrate compost into the landfill cover design in order to establish a biocover that is optimized for biological oxidation of methane (CH4). A laboratory and field investigation was performed to quantify respiration...... in an experimental compost biocover in terms of oxygen (O2) consumption and carbon dioxide (CO2) production and emission rates. O2 consumption and CO2 production rates were measured in batch and column experiments containing compost sampled from a landfill biowindow at Fakse landfill in Denmark. Column gas...

  12. From California dreaming to California data: Challenging historic models for landfill CH4 emissions

    Directory of Open Access Journals (Sweden)

    Kurt Spokas

    2015-06-01

    Full Text Available Abstract Improved quantification of diverse CH4 sources at the urban scale is needed to guide local GHG mitigation strategies in the Anthropocene. Herein, we focus on landfill CH4 emissions in California, challenging the current IPCC methodology which focuses on a climate dependency for landfill CH4 generation (methanogenesis, but does not explicitly consider climate or soil dependencies for emissions. Relying on a comprehensive California landfill database, a field-validated process-based model for landfill CH4 emissions (CALMIM, and select field measurements at 10 California sites with a variety of methods, we support the contrary position: Limited climate dependency for methanogenesis, but strong climate dependency for landfill CH4 emissions. Contrary to the historic IPCC empirical model for methanogenesis with kinetic constants related to climate, we demonstrate a simpler and more robust linear empirical relationship (r2 = 0.85; n=128 between waste mass and landfill biogas recovery [126 × 10-6 Nm3 CH4 hr-1 Mgwaste-1]. More interestingly, there are no statistically significant relationships with cl