Landfill Gas Recovery Research Articles

Evaluation of Waste Energy Conversion Technology using Analitycal Hierarchy Process in Bantargebang Landfill, Indonesia

In Indonesia, the waste to energy conversion technology has been installed and operate in some landfill, such as Bantargebang landfill where applied landfill gas recovery methods. Evaluate the running process is important to optimize the installed facilities and the other potential technology. This paper aims to evaluate the running process technology in Bantargebang landfill compare with the other waste to energy technology so it can be used as a reference for upgrading technology. Evaluation using Multi Criteria Decision Making techninque with observe method Analitycal Hierarcy Process adopt energy (energy content and net electrical output), environment (MSW reduction and GHG emission), and economic (initial cost and operation maintenance cost) as criterions. The results shows that the anaerobic digestion as alternative technology is the best technology with total point 2.71, followed by inceneration pelletization at second rank with total point 2.70, and running process landfill gas recovery at third rank with total point 2.56.

Potential for energy recovery and greenhouse gas reduction through waste-to-energy technologies

This paper provides a comprehensive analysis of the energy recovery and greenhouse gas (GHG) reduction potentials from solid waste. Based on the current and proposed solid waste management scenarios of Daejeon Metropolitan City in Korea, this study evaluates the energy recovery and GHG reduction potentials of landfill gas recovery, steam heat recovery by incineration, biogas or solid fuel production from organic waste, and solid refuse fuel from solid waste. The results indicate that the energy recovery potential per one ton of waste was largest for solid recovered fuel (SRF) production from municipal solid waste at 2.94 GJ/ton, followed by steam heat generation (2.34 GJ/ton), solid fuel production from sewage sludge (0.77 GJ/ton), biogas production from food waste (0.443 GJ/ton), and landfill gas recovery (0.177 GJ/ton). The energy recovery potentials of all solid waste materials are expected to increase from 252,130 GJ/year in 2012 to 525,540 GJ/ton in 2021. In 2012, GHG reduction by waste-to-energy was 16,061 ton CO2 eq./year; it is predicted to be 33,477 ton CO2 eq./year in 2021.

Hydrate-based Capture of Acidic Gases for Clean Fuels with New Synergic Additives

Abstract The widespread need for the removal of carbon dioxide (CO 2 ) and hydrogen sulfide (H 2 S) from process gas streams associated with hydrogen synthesis plants, upgrading of natural gas, landfill gas recovery, and enhanced oil recovery has led to a continuing interest in developing acid gas separation technologies. This work experimental investigated the hydrate formation processes for capturing acidic gases (CO 2 and H 2 S) from mixture gas (biogas and natural gas) with a new synergic additive, which is composed physical gas solvent (TMS) and traditional hydrate promoter (TBAB). Based on the thermodynamic and kinetic studies, the results show that the hydrate formation process with the synergic additives can capture CO 2 and H 2 S synchronously. The synergic additives not only can considerably moderate the equilibrium hydrate formation conditions, but also make high selectivity of CO 2 and H 2 S over CH 4 during the hydrate formation process, and improve the formation rate and gas storage capacity through their excellent promote effect on the solubility and diffusivity of acidic gases. It will be of practical interest in relation to the fundamental study of enhancing gas hydrate formation and of potential importance for the industry application of gas hydrate.

Waste-to-energy policy in Thailand

ABSTRACTThis paper presents the conversion of waste-to-energy (WtE) in Thailand. The amount of municipal solid waste (MSW) generated in Thailand in 2013 was 26.77 million tons which requires an enormous budget allocation for municipal solid waste management (MSWM). However, the budget is insufficient to provide adequate MSWM services. In order to increase the efficiency, sustainable and environmentally in MSWM, WtE technologies are provided as a solution toward a successful policy. Thailand considers WtE, incineration, refuse derived fuel (RDF), anaerobic digestion, pyrolysis and gasification, and landfill gas recovery to be renewable technologies. These technologies not only reduced the quantity but also improved the quality of waste to meet the required pollution control standards, besides generating a substantial quantity of energy.

Estimation of methane generation from the landfill sites

Landfill Gas (LFG) recovery is a very important element of an integrated solid waste management. The use of the landfills for solid waste disposal will continue to be the predominant method worldwide. This includes the information on how LFG to energy technologies worldwide can be implemented to extract the energy locked up in the landfills. This contributes the consolidation of knowledge in the field of LFG.Provide an overview of the status and prospects of LFG including the technical aspects and benefits of LFG recovery. Estimate of the methane generation estimation once the empirical constants have been determined by using the LFG models.In the present study, various physico-chemical parameters of the MSW were analysed to characterize the waste dumped at Okhla landfill sites in Delhi, India, which shows that it contains a high fraction of degradable organic components. The decomposition of organic components produces methane, a significant contributor to global warming. Based on the waste composition, waste age and the total amount dumped, a first-order model (FOD) was applied to estimate the methane generation potential of the Okhla landfill site, which yields an estimate of 25.98×106 m 3 /year.

Greenhouse gas footprint and the carbon flow associated with different solid waste management strategy for urban metabolism in Bangladesh.

Greenhouse gas (GHG) emissions from municipal solid waste (MSW) and associated climate change consequences are gripping attention globally, while MSW management as a vital subsystem of urban metabolism significantly influences the urban carbon cycles. This study evaluates the GHG emissions and carbon flow of existing and proposed MSW management in Bangladesh through scenario analysis, including landfill with landfill gas (LFG) recovery, waste to energy (WtE), and material recovery facility (MRF). The analysis indicates that, scenario H2 and H5 emitted net GHGs -152.20kg CO2 eq. and -140.32kg CO2 eq., respectively, in comparison with 420.88kg CO2 eq. of scenario H1 for managing per ton of wastes during the reference year 2015. The annual horizontal carbon flux of the waste input was 319Gg and 158Gg during 2015 in Dhaka and Chittagong, respectively. An integrated strategy of managing the wastes in the urban areas of Bangladesh involving WtE incineration plant and LFG recovery to generate electricity as well as MRF could reverse back 209.46Gg carbon and 422.29Gg carbon to the Chittagong and Dhaka urban system, respectively. This study provides valuable insights for the MSW policy framework and revamp of existing MSW management practices with regards to reduction of GHGs emissions from the waste sector in Bangladesh.

Determining the enzyme profile of Burdur Lake isolates

Aerobic CH4 oxidation plays an important role in mitigating CH4 release from landfills to the atmosphere. Therefore, in this study, oxidation activity and community of methanotrophs were investigated in a subtropical landfill. Among the three sites investigated, the highest CH4 concentration was detected in the landfill cover soil of the site (A) without a landfill gas (LFG) recovery system, although the refuse in the site had been deposited for a longer time (∼14–15 years) compared to the other two sites (∼6–11 years) where a LFG recovery system was applied. In April and September, the higher CH4 flux was detected in site A with 72.4 and 51.7 g m−2 d−1, respectively, compared to the other sites. The abundance of methanotrophs assessed by quantification of pmoA varied with location and season. A linear relationship was observed between the abundance of methanotrophs and CH4 concentrations in the landfill cover soils (R = 0.827, P < 0.001). The key factors influencing the methanotrophic diversity in the landfill cover soils were pH, the water content and the CH4 concentration in the soil, of which pH was the most important factor. Type I methanotrophs, including Methylococcus, Methylosarcina, Methylomicrobium and Methylobacter, and type II methanotrophs (Methylocystis) were all detected in the landfill cover soils, with Methylocystis and Methylosarcina being the dominant genera. Methylocystis was abundant in the slightly acidic landfill cover soil, especially in September, and represented more than 89% of the total terminal-restriction fragment abundance. These findings indicated that the LFG recovery system, as well as physical and chemical parameters, affected the diversity and activity of methanotrophs in landfill cover soils.

ENHANCING LANDFILL GAS RECOVERY- A REVIEW

Although landfills serve as an easy and very economic means for disposing wastes, it poses threat to the environment as it generates both leachate and greenhouse gases, including methane (CH4) and carbon dioxide (CO2). Nowadays, landfills are equipped with gas recovery components thereby making it possible for more methane gas to be collected and used as an alternative source of green energy. Currently, various technologies have been employed in managing landfill sites in order to attenuate environmental degradation; Revegetation technologies, methane oxidation, anaerobic digestion, waste washing and pre-treatment are some of the methods currently used. This review presents an overview of the technologies and methods employed for enhancing landfill gas mitigation and recovery.

Attitudes toward waste to energy facilities and impacts on diversion in Ontario, Canada

Despite progress in residential waste diversion, residual waste – that fraction which cannot be recycled or composted – must continue to be managed by municipalities. Zero waste and environmental groups worry that waste-to-energy (WtE) incinerators discourage diversion, while both incineration and landfill have been stigmatized in the popular consciousness such that WtE incinerators in particular are being cancelled more often than they are approved. We conducted a mail-back survey of 217 residents in Toronto, Durham and Peel, Ontario, to understand attitudes toward diversion, levels of support for WtE incineration and WtE landfill (landfill gas recovery) facilities, and predictors of facility support. Contrary to experiences elsewhere, diversion seems threatened by WtE when measured as attitudes with 18%, and 14% agreeing that they would be less inclined to divert recyclable/compostable materials if they knew materials went to a WtE landfill or incinerator. When forced to choose between four options landfill or incineration with and without energy recovery, WtE incineration is most preferred (65%) and landfill without WtE is the least preferred option (61%). However, measurement has a large influence on public opinion results in the sense that support for WtE incineration drops to 43% when asked as a “vote in favor” question and to only 36% when measured as a 4-item index of support. When the indexes of support for landfill and WtE incineration are modeled, the prominence of odor in the landfill model distinguishes it from the WtE incinerator model which is dominated more by community and concern about health effects. Implications for policy are discussed, particularly mandatory diversion targets to accompany WtE.

Increasing the application of gas engines to decrease China’s GHG emissions

This paper employs a review of the technical literature to estimate the potential decrease in greenhouse gas (GHG) emissions that could be achieved by increasing the application of gas engines in China in three sectors: urban public transport vehicle; shipping; and thermal power plants. China’s gas engine development strategies and three types of gas resource are discussed in the study, which indicates that gas engines could decrease GHG emissions by 520 megatonnes (Mt) of carbon dioxide equivalent (CO2e) by 2020. This would account for 9.7 % of the government’s target for decreasing GHG emissions and is dominated by methane recovery from the use of coal mine gas (CMG) and landfill gas (LFG) for power generation. In the public urban transport vehicle and shipping sectors the low price of natural gas and the increasing demand for the control of harmful emissions could spur the rapid uptake of gas engine vehicles. However, the development of CMG- and LFG-fuelled power plants has been limited by the unwillingness of local enterprises to invest in high-performance gas engine generators and the associated infrastructure. Therefore, further compulsory policies that promote CMG use and LFG recovery should be implemented. Moreover, strict regulations on limiting methane leakage during the production and distribution of gas fuels are urgently needed in China to prevent leakage causing GHG emissions and largely negating the climate benefits of fuel substitution. Strategies for increasing the application of gas engines, promoting gas resources and recovering methane in China are instrumental in global GHG mitigation strategies.

Municipal Solid Waste to Energy Generation in Bangladesh: Possible Scenarios to Generate Renewable Electricity in Dhaka and Chittagong City

Increased generation of methane (CH4) from municipal solid wastes (MSW) alarms the world to take proper initiative for the sustainable management of MSW, because it is 34 times stronger than carbon dioxide (CO2). Mounting land scarcity issue around the world brands the waste to energy (WtE) strategy for MSW management in urban areas as a promising option, because WtE not only reduces the land pressure problem, but also generates electricity, heat, and green jobs. The goal of this study is to evaluate the renewable electricity generation potential and associated carbon reduction of MSW management in Bangladesh using WtE strategies. The study is conducted in two major cities of Bangladesh: Dhaka and Chittagong. Six different WtE scenarios are evaluated consisting of mixed MSW incineration and landfill gas (LFG) recovery system. Energy potential of different WtE strategy is assessed using standard energy conversion model and subsequent GHGs emissions models. Scenario A1results in highest economic and energy potential and net negative GHGs emission. Sensitivity analysis by varying MSW moisture content reveals higher energy potential and less GHGs emissions from MSW possessing low moisture content. The study proposes mixed MSW incineration that could be a potential WtE strategy for renewable electricity generation in Bangladesh.

Opportunities & Challenges in Capturing Landfill Gas from an Active and Un-scientifically Managed Land Fill Site – A Case Study

Currently, nearly 210 Million Metric Tonnes/Annum of Municipal Solid Waste (MSW) is generated in India and most of it gets disposed in Open and un-scientifically managed Landfills. The typical Indian MSW contains approximately 50% of bio-degradable organic components that starts degrading under anaerobic conditions and generates LandFill Gas (LFG). The LFG mainly contains Methane (40-50%) and CO2 (50-60%). Methane is a Green House Gas (GHG), and is 25 times more potent than CO2 in causing Global Warming and is the 2nd largest anthropogenic source of Methane emissions after coal mining. Thus capturing and destructions of LFG shall lead to mitigation of GHG emissions. In addition, open Landfill sites also pose safety risks like fire hazard, explosion, and asphyxiation etc. apart from health risks.At the current MSW generation rate of 0.575MMT/day in India, the LFG generation potential is around 86.25 MMSCMD of LFG. Presently, LFG from the landfill sites is not being captured leading to fugitive GHG emissions. Further, due to rapid population growth and accompanying urbanisation and lack of new landfill sites, the existing waste handling infrastructure is getting stressed and leading to overflowing and vertical growth of the existing landfills. Thus Indian landfills provide good opportunities for the extraction & utilisation of Methane from LFG. However, there are lot of Issues that need to be overcome for exploitation of LFG in a sustainable manner.GAIL (India) Ltd, a Maharatna company, as a part of its R&D activities has taken up an initiative in this direction and implemented a Pilot project to ascertain the recovery of LFG from an un-scientifically managed open active MSW dumping site at Ghazipur Delhi. The utilization of LFG for energy recovery is being explored. This Paper shares the Challenges faced and Key insights gained during the LFG Project Implementation and its Operation.

A multi-criteria analysis of options for energy recovery from municipal solid waste in India and the UK

Energy recovery from municipal solid waste plays a key role in sustainable waste management and energy security. However, there are numerous technologies that vary in suitability for different economic and social climates. This study sets out to develop and apply a multi-criteria decision making methodology that can be used to evaluate the trade-offs between the benefits, opportunities, costs and risks of alternative energy from waste technologies in both developed and developing countries. The technologies considered are mass burn incineration, refuse derived fuel incineration, gasification, anaerobic digestion and landfill gas recovery. By incorporating qualitative and quantitative assessments, a preference ranking of the alternative technologies is produced. The effect of variations in decision criteria weightings are analysed in a sensitivity analysis. The methodology is applied principally to compare and assess energy recovery from waste options in the UK and India. These two countries have been selected as they could both benefit from further development of their waste-to-energy strategies, but have different technical and socio-economic challenges to consider. It is concluded that gasification is the preferred technology for the UK, whereas anaerobic digestion is the preferred technology for India. We believe that the presented methodology will be of particular value for waste-to-energy decision-makers in both developed and developing countries.

A model for gas pressure in layered landfills with horizontal gas collection systems

The recovery and emission of landfill gas (LFG) is an important topic in landfill management. To produce an effective engineering design for an LFG collection system, designers must understand the migration of gas from the waste body to horizontal extraction wells. This paper develops a two-dimensional analytical solution to enable the study of the gas pressure distribution, well pressure and recovery efficiency in layered landfills with horizontal wells. A horizontal layered structure is used to accommodate the non-homogeneity of various municipal solid waste (MSW) aspects with respect to depth, including gas generation, permeability and temperature. The governing equations, subject to boundary and continuity conditions, are solved by using separation of variables and double finite integral transforms. The solution was verified against another analytical solution and a numerical simulation. Subsequently, a sensitivity analysis of single-well model parameters is performed to optimize a double-well system. The results show that a landfill with horizontal collection systems cannot be assumed to be one dimensional with increasing well spacing. Additionally, both the operational vacuum and maximum gas pressure can be reduced through the design of a double- or multiple-well system. Therefore, the proposed solution can be used for the verification of more complex models and the preliminary design of a horizontal well system.

Energy, economic and environmental (3E) analysis of waste-to-energy (WTE) strategies for municipal solid waste (MSW) management in Malaysia

The utilisation of municipal solid waste (MSW) for energy production has been implemented globally for many decades. Malaysia, however, is still highly dependent on landfills for MSW management. Because of the concern for greenhouse gases (GHG) emission and the scarcity of land, Malaysia has an urgent need for a better waste management strategy. This study aims to evaluate the energy, economic and environmental (3E) impact of waste-to-energy (WTE) for municipal solid waste management. An existing landfill in Malaysia is selected as the case study for consideration to adopt the advanced WTE technologies including the landfill gas recovery system (LFGRS), incineration, anaerobic digestion (AD), and gasification. The study presented an interactive comparison of different WTE scenarios and followed by further discussion on waste incineration and AD as the two potential WTE options in Malaysia. The 3E assessment reveals incineration as the superior technology choice when the production of electricity and heat were considered; however, AD is found to be more favourable under the consideration of electricity production only.

Potential Contribution of Waste-to-Energy to Power Consumption in the Gaza Strip

Sustainable energy supply is one of the main challenges that people will face over the coming decades. Biomass can make a substantial contribution to supplying future energy demand in a sustainable way. Currently it is the largest global contributor of renewable energy, and has significant potential to expand the production of heat, electricity and fuels for transport. Municipal solid waste is an enormous renewable resource that has high energy capacity because it contains a high proportion of biomass materials. This kind of sustainable waste management typically called waste-to-energy is critical for reducing the reliance on fossil fuels and non-renewable materials. Waste-to-energy is a reliable and alternative form of energy that has become the basis for many of the most successful solid waste management systems in many countries. Energy recovery from waste is the conversion of waste materials into useable heat, electricity, or fuel through a variety of processes. This study assesses the potential contribution of waste-to-energy facilities to total Gaza peak power demand up to the year 2040 based on three scenarios: incineration, anaerobic digestion and landfill gas recovery. Three dumping sites are distributed along the Gaza Strip, Johr El-deek, Deir El-balah and Rafah. The analysis shows a potential to produce about 1100 MWh per day based on the anaerobic digestion scenario, about 580 MWh per day based on incineration of municipal solid waste scenario, and about 130 MWh per day based on landfill gas recovery scenario. These values accounts to 275%, 145% and 33% of the year 2014 peak electricity demand of 400 megawatt from the three scenarios, respectively. The forecasted results of the three scenarios can be used to design future waste-to- energy facilities in the main cities of the Gaza Strip. The production cost of energy was 7¢/kWh, 5¢/kWh and 17¢/kWhfor incineration, anaerobic digestion and landfill gas recovery scenarios, respectively.

A two-dimensional gas flow model for layered municipal solid waste landfills

Recovery and utilisation of landfill gas (LFG) can not only reduce the greenhouse effect but also permit the generation of electricity. A good understanding of gas migration from the waste body to the LFG extraction system is required to permit efficient gas recovery. This paper presents an analytical two-dimensional gas flow model to predict the distribution of gas pressure, the CH4 emission flux, the distance of influence and recovery efficiency in landfills. The model is indicative of the flow towards a combined extraction system of vertical wells and horizontal gravel-filled trenches. Moreover, the model has a horizontal layered structure to accommodate anisotropy of municipal solid waste (MSW) and vertical variations in both gas generation rate and permeability. The relevant governing equations for multiple homogenous layers were combined using continuity conditions of gas pressure and flux at the layer interfaces, subjected to realistic boundary conditions, and then solved using an eigenfunction expansion approach. The solution was compared with data available in the literature, and a parametric evaluation was performed to understand the roles of the relevant variables. The results show that, for a non-homogeneous model, the maximum pressure appears at the upper layer of the landfill rather than at the bottom. The location of the maximum pressure depends on the assumptions regarding the vertical distributions of the LFG generation rate and permeability. Additionally, the results can be used to form preliminary estimates of LFG recovery efficiency and overall landfill stability for different waste compositions.

Municipal solid waste (MSW) as a source of renewable energy in Bangladesh: Revisited

Abstract With radically increased population, rapid economic growth and expansion of urbanization and industrialization, mega-cities of Bangladesh are faces the complexity of municipal solid waste (MSW) management. The purpose of this paper is to review the types of MSW that are currently being used for renewable energy sources. To meet up the power supply for city dwellers and reducing space for new landfills, waste-to-energy (WTE) incineration is playing a vital role for renewable energy production from discarded MSW. Incineration of MSW is complex owing to its low calorific value (~3000 kJ/kg) and high water content (~60%). MSW in Bangladesh contains relatively high proportion of organic matter (74.6%) than paper (9.1%) and plastic (3.5%). Using landfill gas recovery process, generation of electricity from MSW in six mega-cities is ~186,408 kW h/day. Therefore, WTE incineration system contributes greater supply of renewable energy in Bangladesh.

Energy and emissions benefits of renewable energy derived from municipal solid waste: Analysis of a low carbon scenario in Malaysia

Ineffective waste management that involves dumping of waste in landfills may degrade valuable land resources and emit methane gas (CH4), a more potent greenhouse gas than carbon dioxide (CO2). The incineration of waste also emits polluted chemicals such as dioxin and particle. Therefore, from a solid waste management perspective, both landfilling and incineration practices pose challenges to the development of a green and sustainable future. Waste-to-energy (WtE) has become a promising strategy catering to these issues because the utilisation of waste reduces the amount of landfilled waste (overcoming land resource issues) while increasing renewable energy production. The goal of this paper is to evaluate the energy and carbon reduction potential in Malaysia for various WtE strategies for municipal solid waste (MSW). The material properties of the MSW, its energy conversion potential and subsequent greenhouse gases (GHG) emissions are analysed based on the chemical compositions and biogenic carbon fractions of the waste. The GHG emission reduction potential is also calculated by considering fossil fuel displacement and CH4 avoidance from landfilling. In this paper, five different scenarios are analysed with results indicating a integration of landfill gas (LFG) recovery systems and waste incinerator as the major and minor WtE strategies shows the highest economical benefit with optimal GHG mitigation and energy potential. Sensitivity analysis on the effect of moisture content of MSW towards energy potential and GHG emissions are performed. These evaluations of WtE strategies provides valuable insights for policy decision in MSW management practices with cost effective, energy benefit, environmental protection.

Analysis of the feasibility of the recovery of landfill gas: a case study of Mexico

Abstract Electricity is a vital component in the development of societies and industrial progress. The growing demand and environmental degradation from current sources forces us to search for alternative methods of generating it. The use of biogas generated in landfills enables the recovery of the remaining energy in waste and reduces the environmental problems caused by burning coal, oil, and natural gas. Certainty in the generation projections is required for an energy source to be considered useful. The usefulness of biogas power generation depends on accurately estimating the amount of possible biogas generation. Considering this uncertainty, the objectives of this research were to (a) determine the methane generation rate ( k ) and methane generation potential ( L 0 ), and (b) estimate the biogas generation in the final disposal sites (FDS) of two urban communities and two rural communities in Baja California, Mexico. To determine the constants used in biogas models, the following experiments were performed: (a) waste characterisation studies, (b) observations of the characteristics and performance of the FDS, (c) interviews with the managers of the FDS, and (d) IPCC model parameters. Predictions of biogas utility were made using the modified constants in the Mexico LFG Model Version 2.0 proposed by SCS Engineers. The results show that k averaged 0.0429 yr −1 and L 0 was 68.69 m 3 /ton. In the period of 2013–2030, there will be a power generation potential of 760492.8 MW/h (USD $142.21 million). The potential reduction in CO 2 e emissions would be approximately 5.2 MtCO 2 e during the same period (USD $57.16 million).