Combined Municipal Solid Waste and biomass system optimization for district energy applications

Municipal Solid Waste (MSW) disposal has been a controversial issue in many countries over the past years, due to disagreement among the various stakeholders on the waste management policies and technologies to be adopted. One of the ways of treating/disposing MSW is energy recovery, as waste is considered to contain a considerable amount of bio-waste and therefore can lead to renewable energy production. The overall efficiency can be very high in the cases of co-generation or tri-generation. In this paper a model is presented, aiming to support decision makers in issues relating to Municipal Solid Waste energy recovery. The idea of using more fuel sources, including MSW and agricultural residue biomass that may exist in a rural area, is explored. The model aims at optimizing the system specifications, such as the capacity of the base-load Waste-to-Energy facility, the capacity of the peak-load biomass boiler and the location of the facility. Furthermore, it defines the quantity of each potential fuel source that should be used annually, in order to maximize the financial yield of the investment. The results of an energy tri-generation case study application at a rural area of Greece, using mixed MSW and biomass, indicate positive financial yield of investment. In addition, a sensitivity analysis is performed on the effect of the most important parameters of the model on the optimum solution, pinpointing the parameters of interest rate, investment cost and heating oil price, as those requiring the attention of the decision makers. Finally, the sensitivity analysis is enhanced by a stochastic analysis to determine the effect of the volatility of parameters on the robustness of the model and the solution obtained.     

Novel and innovative pyrolysis and gasification technologies for energy efficient and environmentally sound MSW disposal

Within the context of European Union (EU) energy policy and sustainibility in waste management, recent EU regulations demand energy efficient and environmentally sound disposal methods of Municipal Solid Waste (MSW). Currently, landfill with its many drawbacks is the preferred option in the EU and many other industrialised countries. Within the waste management hierarchy thermal disposal especially incineration is a viable and proven alternative. But, the dominating method, mass-burn grate incineration has drawbacks as well particularly hazardous emissions and harmful process residues. In recent years, pyrolysis and gasification technologies have emerged to address these issues and improve the energy output. To keep the many players in the field comprehensively informed and up-to-date, novel and innovative technology approaches emphasising European developments are reviewed.     

Report: environmental assessment of Darmstadt (Germany) municipal waste incineration plant.

The focus of this study was the emissions from waste incineration plants using Darmstadt (Germany) waste incineration plant as an example. In the study the emissions generated by incineration of the waste were considered using three different approaches. Initially the emissions from the waste incineration plant were assessed as part of the impact of waste management systems on the environment by using a Municipal Solid Waste Management System (MSWMS) assessment tool (also called: LCA-IWM assessment tool). This was followed by a comparison between the optimal waste incineration process and the real situation. Finally a comparison was made between the emissions from the incineration plant and the emissions from a vehicle.     

Material and energy recovery in integrated waste management systems: the potential for energy recovery

This article is part of a set of six coordinated papers reporting the main findings of a research project carried out by five Italian universities on "Material and energy recovery in Integrated Waste Management Systems (IWMS)". An overview of the project and a summary of the most relevant results can be found in the introductory article of the series. This paper describes the work related to the evaluation of mass and energy balances, which has consisted of three major efforts (i) development of a model for quantifying the energy content and the elemental compositions of the waste streams appearing in a IWMS; (ii) upgrade of an earlier model to predict the performances of Waste-to-Energy (WtE) plants; (iii) evaluation of mass and energy balances of all the scenarios and the recovery paths considered in the project. Results show that not only the amount of material available for energy recovery is significantly higher than the Unsorted Residual Waste (URW) left after Separate Collection (SC), because selection and recycling generate significant amounts of residues, but its heating value is higher than that of the original, gross waste. Therefore, the energy potential of what is left after recycling is always higher than the complement to 100% of the Source Separation Level (SSL). Also, increasing SSL has marginal effects on the potential for energy recovery: nearly doubling SSL (from 35% to 65%) reduces the energy potential only by one fourth. Consequently, even at high SSL energy recovery is a fundamental step of a sustainable waste management system. Variations of SSL do bring about variations of the composition, heating value and moisture content of the material fed to WtE plants, but these variations (i) are smaller than one can expect; (ii) have marginal effects on the performances of the WtE plant. These considerations suggest that the mere value of SSL is not a good indicator of the quality of the waste management system, nor of its energy and environmental outcome. Given the well-known dependence of the efficiency of steam power plants with their power output, the efficiency of energy recovery crucially depends on the size of the IWMS served by the WtE plant. A fivefold increase of the amount of gross waste handled in the IWMS (from 150,000 to 750,000 tons per year of gross waste) allows increasing the electric efficiencies of the WtE plant by about 6-7 percentage points (from 21-23% to 28.5% circa).     

Matrix method for evaluation of existing solid waste management system in Himachal Pradesh,India

Journal of Material Cycles and Waste Management - Effective management of Municipal Solid Waste (MSW) is an essential function of the city municipal corporation. The present study reports on the...     

Municipal solid waste management: Identification and analysis of engineering indexes representing demand and costs generated in virtuous Italian communities

The definition and utilisation of engineering indexes in the field of Municipal Solid Waste Management (MSWM) is an issue of interest for technicians and scientists, which is widely discussed in literature. Specifically, the availability of consolidated engineering indexes is useful when new waste collection services are designed, along with when their performance is evaluated after a warm-up period. However, most published works in the field of MSWM complete their study with an analysis of isolated case studies. Conversely, decision makers require tools for information collection and exchange in order to trace the trends of these engineering indexes in large experiments. In this paper, common engineering indexes are presented and their values analysed in virtuous Italian communities, with the aim of contributing to the creation of a useful database whose data could be used during experiments, by indicating examples of MSWM demand profiles and the costs required to manage them.     

Assessment of an appropriate integrated waste management plan targeting the Circular Economy based on the LCA method

Journal of Material Cycles and Waste Management - Rapid population growth and urbanization increase the Municipal Solid Waste (MSW) generation rate and the demand for natural resources. In order to...     

The development of landfill operation and management in Indonesia

Journal of Material Cycles and Waste Management - The enactment of the Waste Act in 2008 represents a milestone in Indonesian waste management legislation, particularly in relation to landfill...     

Cogeneration from thermal treatment of selected municipal solid wastes. A stoichiometric model building for the case study on Palermo

This paper aims to calculate the energetic and environmental effects of an integrated solid waste management system in Palermo, Italy. In particular, the thermal treatment of Municipal Solid Waste (MSW) with energy recovery is assessed. The current characterization at the local scale is taken into account. Two different options of collection are taken into account: (1) unselected wastes; and (2) sorted collection, according to the current Italian regulation. Combustion process is analyzed and the following features are calculated: (1) stoichiometric content of air and air excess; and (2) temperature and enthalpy of flue gases. Energy recovery is performed in the hypothesis of Hirn cycle both with steam condensation to produce only power, and with bleeding cycle for the combined production of power and thermal energy. Total electric efficiency is assumed as representative index of the technological level of the assessed plant. Results show that the thermal treatment of selected MSW, associated with a cogenerative recovery of energy, represents a relevant sustainable strategy of waste valorization as an alternative to fossil fuels.     

Prediction of heavy metals concentration in the leachate: a case study of Ukrainian waste

Journal of Material Cycles and Waste Management - A lifetime of landfill with the waste composition and conditions specific to big and small towns of Ukraine is reproduced with landfill simulation...     

An integrated analytical framework for quantifying the LCOE of waste-to-energy facilities for a range of greenhouse gas emissions policy and technical factors

This study presents a novel integrated method for considering the economics of waste-to-energy (WTE) facilities with priced greenhouse gas (GHG) emissions based upon technical and economic characteristics of the WTE facility, MSW stream, landfill alternative, and GHG emissions policy. The study demonstrates use of the formulation for six different policy scenarios and explores sensitivity of the results to ranges of certain technical parameters as found in existing literature. The study shows that details of the GHG emissions regulations have large impact on the levelized cost of energy (LCOE) of WTE and that GHG regulations can either increase or decrease the LCOE of WTE depending on policy choices regarding biogenic fractions from combusted waste and emissions from landfills. Important policy considerations are the fraction of the carbon emissions that are priced (i.e. all emissions versus only non-biogenic emissions), whether emissions credits are allowed due to reducing fugitive landfill gas emissions, whether biogenic carbon sequestration in landfills is credited against landfill emissions, and the effectiveness of the landfill gas recovery system where waste would otherwise have been buried. The default landfill gas recovery system effectiveness assumed by much of the industry yields GHG offsets that are very close to the direct non-biogenic GHG emissions from a WTE facility, meaning that small changes in the recovery effectiveness cause relatively larger changes in the emissions factor of the WTE facility. Finally, the economics of WTE are dependent on the MSW stream composition, with paper and wood being advantageous, metal and glass being disadvantageous, and plastics, food, and yard waste being either advantageous or disadvantageous depending upon the avoided tipping fee and the GHG emissions price.     

Policy implementation of the Republic Act (RA) No. 9003 in the Philippines: A case study of Cebu city

Municipal Solid Waste Management (MSWM) is considered to be one of the most serious environmental issues in the Philippines. The annual waste generation was estimated at 10.6 million tonnes in 2012 and this is expected to double in 2025. The Republic Act (RA) No. 9003, widely known as the Ecological Solid Waste Management Act of 2000, provides the required policy framework, institutional mechanisms and mandate to the Local Government Units (LGUs) to achieve 25% waste reduction target through establishing an integrated solid waste management plan based on the 3Rs (reduce, reuse and recycling). Although the initial impact of the LGUs is still very limited in implementing the national mandate, this article highlights the successful experiences of Cebu, the second largest city in the Philippines, in reducing its MSW generation by more than 30% in the past three years. This study also explores the implementation process, innovative actions taken by the Cebu City Government in implementing the national mandate at local level and identifies the factors that influence the policy implementation. The findings suggest that the impacts of the national mandate can be achieved if the LGUs have the high degree of political commitment, planning and development of effective local strategies in a collaborative manner to meet with local conditions, partnership building with other stakeholders, capacity development, adequate financing and incentives, and in the close monitoring and evaluation of performance.     

Life cycle greenhouse gas emissions of emerging municipal solid waste management options: a case study in Thailand

Journal of Material Cycles and Waste Management - Landfilling is the main technology for municipal solid waste (MSW) disposal in Thailand. Semi-aerobic landfill and mechanical biological treatment...     

Waste to energy: a decision-making process for technology selection through characterization of waste,considering energy and emission in the city of Ahmedabad,India

Journal of Material Cycles and Waste Management - Municipal solid waste (MSW) disposal has become major issue for the city of Ahmedabad, India. Development, concentrated population and economic...     

Nitrogen management in landfill leachate: Application of SHARON,ANAMMOX and combined SHARON–ANAMMOX process

In today’s context of waste management, landfilling of Municipal Solid Waste (MSW) is considered to be one of the standard practices worldwide. Leachate generated from municipal landfills has become a great threat to the surroundings as it contains high concentration of organics, ammonia and other toxic pollutants. Emphasis has to be placed on the removal of ammonia nitrogen in particular, derived from the nitrogen content of the MSW and it is a long term pollution problem in landfills which determines when the landfill can be considered stable. Several biological processes are available for the removal of ammonia but novel processes such as the Single Reactor System for High Activity Ammonia Removal over Nitrite (SHARON) and Anaerobic Ammonium Oxidation (ANAMMOX) process have great potential and several advantages over conventional processes. The combined SHARON–ANAMMOX process for municipal landfill leachate treatment is a new, innovative and significant approach that requires more research to identify and solve critical issues. This review addresses the operational parameters, microbiology, biochemistry and application of both the processes to remove ammonia from leachate.     

Changing scenario of municipal solid waste management in Kanpur city,India

Journal of Material Cycles and Waste Management - Generation of municipal solid waste (MSW) depends upon lifestyle, urbanization and income level of population. Solid waste management is one of the...     

Application of analytical hierarchy process (AHP) to assess options of energy recovery from municipal solid waste: a case study in Tehran,Iran

Journal of Material Cycles and Waste Management - In the current study, a model was established based on AHP method for assessment of different alternatives for energy recovery from the waste in...     

Environmental impacts of residual Municipal Solid Waste incineration: A comparison of 110 French incinerators using a life cycle approach

Incineration is the main option for residual Municipal Solid Waste treatment in France. This study compares the environmental performances of 110 French incinerators (i.e. 85% of the total number of plants currently in activity in France) in a Life Cycle Assessment perspective, considering 5 non-toxic impact categories: climate change, photochemical oxidant formation, particulate matter formation, terrestrial acidification and marine eutrophication. Mean, median and lower/upper impact potentials are determined considering the incineration of 1 tonne of French residual Municipal Solid Waste. The results highlight the relatively large variability of the impact potentials as a function of the plant technical performances. In particular, the climate change impact potential of the incineration of 1 tonne of waste ranges from a benefit of ?58 kg CO₂-eq to a relatively large burden of 408 kg CO₂-eq, with 294 kg CO₂-eq as the average impact. Two main plant-specific parameters drive the impact potentials regarding the 5 non-toxic impact categories under study: the energy recovery and delivery rate and the NO_x process-specific emissions. The variability of the impact potentials as a function of incinerator characteristics therefore calls for the use of site-specific data when required by the LCA goal and scope definition phase, in particular when the study focuses on a specific incinerator or on a local waste management plan, and when these data are available.     

Inventory of twenty-six combustible wastes as sources of potentially toxic elements: B,Cr, Cu,Zn, As,Sb, Ba,and Pb

Journal of Material Cycles and Waste Management - Municipal solid waste (MSW) is converted to various materials through treatment processes, which in turn distributes potentially toxic elements...     

Mitigating greenhouse gas emissions of municipal solid waste management system: case study of Chengdu,China

Journal of Material Cycles and Waste Management - Municipal solid waste management has become a worldwide concern. Chengdu municipality has decided to adopt the “zero landfilling”...