Waste Incineration Plants Research Articles

Two-step process to recover metal and mineral residues from municipal solid waste incinerated (MSWI) ashes

The utilization potential of mineral fractions after metal recovery from fly ash and air pollution control residues from a municipal solid waste incineration plant was studied. Chemical leaching using acidic (H2SO4), and alkaline (NaOH) solutions was applied for metal recovery from fly ash and air pollution control residues from a municipal solid waste incineration plant. Subsequently, the feasibility of recycling both untreated and treated samples in cementitious materials was evaluated. This study aims to investigate the influences of chemical leaching on the structures and properties of MSWI residues as well as examine the utilization potential in cementitious materials of mineral residues after leaching, and their environmental risk. The use of acidic and alkaline leachants had good efficiency in critical metal recovery and unvalued/hazardous metal removal: 99 % of As, 72–80 % of Cd, 47–60 % of Zn, Cu, Co or Mn. After leaching, the chemical composition, physical properties, and mineralogical phases of the incinerated residues were substantially modified. The postleaching mineral residues showed potential for use in supplementary cementitious materials with enhanced reactivity and control of hydration kinetics. The compressive strength of cement pastes using 20 % of MSWI residues can obtain 14 MPa after 7 days. Detrimental impacts from potential toxic elements in incinerated residues can be alleviated through chemical leaching.

Enhancing concrete pavement performance using refuse derived fuel fly ash as a sustainable cementitious material

ABSTRACT The utilization of waste materials in concrete is becoming increasingly important for sustainability in construction. This research investigated the mechanical performance and environmental safety of concretes containing Refuse Derived Fuel fly ash (RDF FA), a waste product from waste incineration plants. The innovative mix design strategically used RDF FA as both cement replacement and cementitious addition in concrete. Compressive and flexural strength test results showed that RDF FA addition increased both compressive and flexural strengths, while RDF FA replacement decreased strengths (< 28 days cured) compared to those of traditional cement concrete. Microstructural and mineralogical analyses revealed dense C–S-H formation in RDF FA added samples, indicating improved hydration. In contrast, RDF FA replacement reduced cementitious products and hindered hydration. RDF FA’s high SiO2 content and favourable SiO2/CaO ratio enhanced pozzolanic reaction in RDF FA added samples, further improving strength development. Leaching test results demonstrated that heavy metal concentrations in RDF FA-modified concretes remained within environmental protection limits. Thus, with proper mix design, RDF FA has the potential to be a sustainable supplement for concrete, reducing industrial waste and natural resource use. This work provides an approach to balance enhanced concrete performance with environmental safety when using RDF FA.

Destructive Effects of Slag from Municipal Waste Incineration Plants on Cement Composites.

The increasing production of solid waste and the scarcity of natural aggregates as a matter of fact have made waste recycling a necessity. One such waste, which is generated in large quantities, is slag. However, slag from incineration plants may contain harmful elements that adversely affect the physical, chemical and mechanical properties of cement composites. This study presents laboratory research results on the effect of slag from the Poznan Municipal Waste Thermal Conversion Plant (Poland) on the physicochemical properties of cement composites. The samples were analyzed by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). It was shown that the slag analyzed contained significant amounts of aluminum, which had a direct effect on the structure of the concrete. An example of this influence is the release of hydrogen during reactions, which causes swelling and cracking of the concrete and reduces its mechanical strength. The authors emphasize that waste aggregate (slag) can be effectively used in the production of concrete after appropriate processing that reduces the risk of adverse effects.

Simplified mathematical model of oxy-fuel combustion of municipal solid waste in the grate furnace: effect of different flue gas recirculation rates and comparison with conventional mode

Bioenergy carbon capture technology (BioCCS or BECCS) plays a key role in the European Green Deal, which aims to decarbonize industry and energy sectors, resulting in the production of energy with negative CO2 emissions. Due to the biogenic origin of carbon contained in municipal solid waste (MSW), the application of carbon capture in waste incinera-tion plants can be classified as BioCCS. Thus, this technology has attracted scientists' attention recently since it reduces excessive waste and emissions of carbon dioxide. Currently, there are four incineration plants in the Netherlands, Norway and Japan, in which CO2 capture is implemented; however, they are based on the post-combustion technique since it is the most mature method and not requires many changes in the system. Nevertheless, the separation of CO2 from the flue gas flow, which contains mostly nitrogen, is complex and causes a large drop in the total performance of the system. Oxy-fuel combustion technology involves the replacement of air as an oxidizer into high purity oxygen and recirculated exhaust gas. As a result, CO2-rich gas is produced that is practically ready for capture. The main goal of the study is to develop a math-ematical model of oxy-waste combustion to answer the research questions, such as how the composition of oxidant that is supplied to the process affects the combustion performance. The model includes all important processes taking place within the chamber, such as pyrolysis, char burnout and gas combustion over the grate. The results of the work will contribute to the development of oxy-waste incineration plants and will be useful for design purposes.

Emission of Perfluoroalkyl Acids and Unidentified Organofluorine from Swedish Municipal Waste Incineration Plants

Emission of Perfluoroalkyl Acids and Unidentified Organofluorine from Swedish Municipal Waste Incineration Plants

Numerical Simulation of the Diffusion Characteristics of Odor Pollutants of Waste Bunkers in Waste Incineration Plant

This paper utilizes the waste bunker of a waste incineration plant as the analysis model. It analyzes the airflow characteristics under various unloading door opening states and the air flow velocity through CFD simulation. The simulation analysis results show that when one unloading door is opened, it is recommended to adjust the opening amplitude or set an air outlet to optimize the airflow distribution. If two unloading doors are opened, it is advised to prioritize the two middle unloading doors (M4, M5) or the two rightmost doors (M7, M8). Furthermore, the exhaust port located relatively far from the unloading door should be closed to reduce the turbulence of the airflow. When all unloading doors are opened, the air flow velocity at the unloading door needs to be increased to achieve an efficient exhaust effect and prevent negative pressure problems at low speed. The results offer theoretical support for odor control technologies and provide valuable design recommendations for air outlets and unloading doors in municipal waste incineration plants. Additionally, this study proposes optimization strategies and effective solutions for addressing odor pollutant diffusion in waste incineration facilities.

Waste collection route optimisation for the second waste-to-energy plant in Budapest

The city of Budapest produces approximately 680–700 000 tonnes of municipal solid waste every year, of which <2/3 is being recycled or used for energetic purposes, the rest ends up in a landfill. To combat this environmental and logistical problem the installation of a second waste incineration plant has been proposed in the south of the city. The only cost associated with fuel consumption in the case of waste to energy powerplants (WtE plants) is the transport cost, as the city council provides economic support for waste disposal. Since the transportation has a huge influence on the cost of opertation, logistical optimisation of the transport routes promises a direct impact on cost savings. In this study the logistical optimisation of the Southern Budapest area was carried out using image processing and logic based algorithm programming. As a result the optimal transport of 230 000 tonnes of municipal solid waste (MSW) was solved resulting in a 4 835.2 km monthly travel distance reduction.This value can be translated to 7 823 €/month cost, 9 459.6 kg/month CO2 and 45.3 kg/month NOx emissions reduction in the urban areas.

Improving the method for calculating carbon emissions from waste incineration: confirmed with carbon-14 testing of flue gas

An improved method was developed to calculate direct emissions from seven municipal solid waste incineration plants by adjusting the physical compositions of waste by invoking the proportion of co-incinerated waste and the bottom ash yield. The fossil carbon fractions of the waste components were determined by carbon-14 (14C) testing. Based on the improved method, direct emissions were in the range of 222–610 kg CO2-eq/t waste, corresponding to reductions of 3.4–221 kg CO2-eq/t waste compared with the method without waste composition adjustment. The 14C contents of the flue gas before and after gas cleaning were tested to validate the improved method, and indicated fossil CO2 emissions of 249–446 and 233–405 kg CO2-eq/t waste, respectively. The direct emissions obtained by the improved method were closer to the results of 14C testing, due to more accurate estimations of the actual waste composition. The method was further combined with a life cycle analysis of the waste incineration process, obtaining total carbon emissions in the range from –33.2 to 483 kg CO2-eq/t waste. The findings provide a new means of accurately calculating carbon emissions from waste incineration.Graphical

Low-Temperature NH3-SCR Technology for Industrial Application of Waste Incineration: An Overview of Research Progress

Selective catalytic reduction of nitrogen oxides with NH3 (NH3-SCR) was investigated deeper and deeper with poisoning factors such as H2O, SO2, heavy metals, etc. In order to remove the reheating process before the SCR reactor, the application trend of NH3-SCR technology in the non-power industry is concentrated on the condition of low temperature even ultra-low temperature. The present study summarizes the research process of SO2 and H2O resistance of NH3-SCR catalysts under low temperatures related to the working conditions of municipal solid waste incineration plants. In detail, the effects of a high content of H2O and low concentration of SO2 are reviewed. Other factors such as heavy metals, alkali, or alkaline earth metals in the reaction system, synergistic removal of NOx, polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) are addressed. Finally, the catalytic performance of assembled monolithic catalysts and pilot-scale experiments are also analyzed for the possibility of industrial application. Hopefully, in view of the questions outlined in this study, valuable insights could be taken into consideration for the development of NH3-SCR in waste incineration.

Energy and Economic Analysis of a New Combination Cascade Waste Heat Recovery System of a Waste-to-Energy Plant

Waste incineration has become the main treatment method for urban household waste, and it can produce a large amount of electricity. The efficiency of waste incineration plants is reduced due to the large amount of waste heat carried away by the flue gas. Recycling and utilizing the waste heat from flue gas are important in improving the economic benefits of waste incineration, which is necessary for energy conservation and emission reduction. Based on the principle of cascade waste heat recovery from waste incineration flue gas whilst considering system safety and efficiency, this study proposed a new combination cascade waste heat recovery system consisting of a Rankine cycle, an organic Rankine cycle and a heat pump cycle. Thermodynamic and economic analyses of the combined system were conducted in detail. The results indicated that the energy efficiency of the combined system could reach up to 73%. The maximum net present value of the system was million USD 1.59 million, and the dynamic investment payback period was about 6.5 years. The isentropic efficiency of the combined system’s pumps and turbines had a significant impact on the system’s performance. A higher isentropic efficiency resulted in better system performance. The exergy analysis showed that the evaporator of the heat pump system had the highest irreversible loss.

Unveiling the competitive mechanism between SO2 and PCDD/Fs on activated carbon adsorption

In municipal solid waste incineration (MSWI) plants, activated carbon (AC) adsorption is the key technique for eliminating Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) from flue gases. This research thoroughly investigates the potential competitive adsorption between SO2 and PCDD/Fs and examines how adsorption at the center and the edge of the AC layer impacts the adsorption process. The findings show a decline in the removal efficiency of PCDD/Fs from 86.8 % to 84.2 % and further to 74.4 % when using SO2 pre-treated (AC-A3) and H2SO4-impregnated (AC-B2) activated carbon, respectively. Multiple characterization methods reveal that sulfur elements occupy active sites within the inner pores of the activated carbon, reducing the availability of its pore structure, particularly affecting microporous more than mesoporous structures. DFT calculations suggest that the π-π EDA effect facilitates the adsorption of 2,3,7,8-Tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD), whereas dispersion force drive SO2 adsorption. Comparisons among various oxygenated functional groups show that the organic acid anhydride (CO-CO) has better adsorption selectivity toward TCDD and less adsorption to SO2. This study provides a novel perspective on the adsorption mechanisms of PCDD/Fs on AC and the competitive dynamics of sulfur in the flue gas.

Enhanced hybrid LSTM and SLAR modeling for in-depth analysis of temporal and spatial patterns in compositional data for environmental monitoring

A novel methodology for analyzing compositional data (CoDa) integrates long short-term memory (LSTM) networks with spatial lag autoregressive (SLAR) models to simultaneously capture temporal and spatial patterns. The proposed approach leverages LSTM’s strengths in handling temporal relationships and SLAR’s ability to capture spatial correlations, employing the centered log-ratio (CLR) transformation to manage CoDa’s characteristics, making it suitable for advanced analysis. The Adam optimizer ensures efficient and stable model training, enhancing convergence speed and precision. The combined approach involves preprocessing CoDa with CLR, initializing LSTM layers, performing forward passes through LSTM, integrating the SLAR model, generating outputs, post-processing data, calculating loss, and performing backpropagation. The methodology’s effectiveness is demonstrated through a case study on pollutant emissions data from a waste incineration plant, focusing on key pollutants such as Dioxins and Furans, Heavy Metals (Hg, Pb, Cd), Nitrogen Oxides (NO), Sulfur Dioxide (SO), Particulate Matter (PM), and Carbon Monoxide (CO). The LSTM network, configured with two hidden layers, dynamically adjusts learning rates for faster convergence. Integrating SLAR improves spatial pattern accounting, significantly enhancing predictive accuracy. Comparative analysis shows substantial performance metric improvements over standard LSTM models, with the LSTM-SLAR model reducing errors and explaining a higher proportion of data variability. In process safety and risk engineering, the proposed methodology enhances pollutant emission monitoring and control, enables proactive risk management, ensures regulatory compliance, and improves risk assessment accuracy, making it invaluable for dynamic risk assessment in environmental monitoring and is broadly applicable to fields requiring detailed temporal and spatial analysis, demonstrating robustness and versatility in handling complex CoDa.

Utilization of Municipal Solid Waste Incineration (MSWIFA) in Geopolymer Concrete: A Study on Compressive Strength and Leaching Characteristics.

This study explores the utilization of municipal solid waste incineration fly ash (MSWIFA) in geopolymer concrete, focusing on compressive strength and heavy metal leachability. MSWIFA was sourced from a Shenzhen waste incineration plant and pretreated by washing to remove soluble salts. Geopolymer concrete was prepared incorporate with washed or unwashed MSWIFA and tested under different pH conditions (2.88, 4.20, and 10.0). Optimal compressive strength was achieved with a Si/Al ratio of 1.5, water/Na ratio of 10, and sand-binder ratio of 0.6. The washing pretreatment significantly enhanced compressive strength, particularly under alkaline conditions, with GP-WFA (washed MSWIFA) exhibiting a 49.6% increase in compressive strength, compared to a 21.3% increase in GP-FA (unwashed MSWIFA). Additionally, GP-WFA's compressive strength reached 41.7 MPa, comparable to that of the control (GP-control) at 43.7 MPa. Leaching tests showed that acidic conditions (pH 2.88) promoted heavy metal leaching, which increased over the leaching time, while an alkaline environment significantly reduced the leachability of heavy metals. These findings highlight the potential of using washed MSWIFA in geopolymer concrete, promoting sustainable construction practices, particularly in alkaline conditions.

Optimization and Analysis of Excess Heat Utilization from an Exhaust Outlet in a Waste Incinerator Plant : Case Study of The Hydro Drive Incinerator, West Java, Indonesia

Optimization and Analysis of Excess Heat Utilization from an Exhaust Outlet in a Waste Incinerator Plant : Case Study of The Hydro Drive Incinerator, West Java, Indonesia

Failure analysis of grate in a municipal solid waste incineration plant

The paper presents findings on the mechanisms and consequences of high-temperature corrosion in a waste incineration plant, particularly focusing on the corrosion of gratings made of duplex cast steel. The structure is crucial for corrosion resistance. Symptoms of this corrosion include scale formation and removal, characterized by a two-zone composition: an outer part containing elements such as magnesium, calcium, aluminium, silicon, and oxygen, and an inner part consisting of chromium oxide and iron oxide. Melting traces caused by corrosion in molten salts are also observed on the surface of the scale, and intergranular corrosion and internal oxidation are observed on the cross-section of the grating. Additionally, precipitation processes occur due to long-term heating, leading to the formation of Cr23C6, G and σ phases. These findings underscore the challenges posed by high-temperature corrosion in industrial settings and highlight the complex mechanisms involved in the degradation of materials under such conditions.

Characteristics and release potential of microplastics in municipal solid waste incineration bottom ash

Incineration is an effective method for reducing and safely treating municipal solid waste. However, microplastics (MPs) inevitably remain in the bottom ash, potentially introducing new pollution risks during subsequent treatment processes. This study conducted an analysis of the accumulation and release potential of MPs in bottom ash samples collected from 4 municipal solid waste incineration plants in Zhejiang, China. The results showed that the abundance of MPs ranged from 20 to 118 items g−1. Remarkably, MPs were found to accumulate predominantly in smaller bottom ash particles below 4.75 mm accounted for up to 70% of the total MPs. Most MPs in the bottom ash were under 100 μm in size, with a majority exceeding 50% being less than 50 μm, typically manifesting as shafts and fibers. In scenarios of secondary crushing, the abundance of MPs increased gradually with the degree of bottom ash crushing. When bottom ash was crushed to a particle size of less than 0.6 mm, the abundance of MPs reached up to 87–901 items g−1, which is 5–10 times higher than the original bottom ash. It is estimated that the annual release of MPs may reach up to 4.05 × 1016 particles. Re-incinerating thoroughly crushed bottom ash at 600 °C successfully decomposed the MPs. Mechanical stress can significantly increase the risk of MPs releasing in bottom ash. This risk can be eliminated by using secondary incineration to achieve complete MPs decomposition.

Calcium oxide adsorption of gas phase PCDD/Fs and its impact on the adsorption properties of activated carbon

Calcium oxide (CaO), utilized in semi-dry/dry desulfurization systems at municipal solid waste incineration (MSWI) plants, demonstrates some capability to remove polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). This study assessed the gas-phase PCDD/F removal performance of CaO, activated carbon (AC) and CaO-AC mixtures. Alone, CaO achieved removal efficiencies of only 31.9% for mass and 50.8% for I-TEQ concentration. However, CaO-AC mixtures exhibited significantly higher efficiencies, reaching 96.0% and 92.5% for mass and I-TEQ concentrations, respectively, surpassing those of AC alone, which were 74.7% and 58.5%. BET analysis indicated that CaO's limited surface area and pore structure are major constraints on its adsorption performance. Density functional theory (DFT) calculations revealed that the π-π electron donor-acceptor (EDA) interaction enhances the adsorption between AC and PCDD/F, with adsorption energies ranging from −1.02 to −1.24 eV. Additionally, the induced dipole interactions between CaO and PCDD/F contribute to adsorption energies ranging from −1.13 to −1.43 eV. Moreover, with increasing chlorination levels, PCDD/F molecules are more predisposed to accept electron transfers from the surfaces of AC or CaO, thereby facilitating adsorption. The calculation for mixed AC and CaO showed that CaO modifies AC's properties, enhancing its ability to adsorb gas phase PCDD/Fs, with the higher adsorption energy and more electrons transfer, aligning with gas phase PCDD/Fs adsorption experiments. This study provides a comprehensive understanding of how CaO influences the PCDD/F adsorption performance of AC.

EU Regulatory Compliance of Renewable Fuels from Steel Mill Gases and Exhaust Gases

AbstractThe production of renewable and sustainable fuels must comply with the EU regulatory framework (Renewable Energy Directive (EU) 2023/2413, Commission Delegated Regulations (EU) 2023/1184, and (EU) 2023/1185) for the use of renewable energy in the transport sector. The utilization of steel mill gases (SMGs) and alternative CO2 sources (waste incineration plants (WIPs), lime industry) to produce renewable fuels of non‐biological origin (RFNBOs) and recycled carbon fuels (RCFs) are attractive options as a high share of RFNBOs can be achieved with a significant reduction in greenhouse gas (GHG) emissions compared to fossil fuel use.

Technological and economical analysis of the heat recovery system from flue gas in a thermal waste treatment plant

A heat recovery system from flue gas increases the overall efficiency of a district heating or CHP plant, as the system recovers the waste energy contained in the flue gas at the chimney outlet. This makes it possible to increase thermal energy production with the same fuel consumption. A method for calculating the thermodynamic parameters of municipal waste incineration plants was developed as part of the work carried out. The mathematical models prepared made it possible to analyse the impact of the heat recovery system from flue gas on technical and economic parameters and the environment, including, among other things, an estimate of the annual amount of heat recovered, the amount of additional electricity consumed, the amount of condensate treated, the estimated capital expenditure, operating profits and operating costs. The results of the analyses were the basis for designing and constructing a heat recovery system from flue gas equipped with a condensation heat exchanger for the municipal waste incineration plant in Cracow. The calculation results were compared with the measurement results obtained during the test run of the constructed installation.

Production of Sustainable Methanol from Industrial Exhaust Gases

AbstractCarbon capture and utilization (CCU) is part of the European Union (EU)’s strategy to become climate‐neutral by 2050. CO2 is needed as a feedstock for the production of climate‐friendly base chemicals and sustainable fuels. Although CO2 capture from industrial point sources is technically feasible and requires less energy than direct air capture, its integration into the circular economy is challenging due to only the temporary recognition of fossil CO2 as a source for the production of climate‐friendly renewable fuels. In this article, CO2 sources such as waste incineration plants, lime production, and steel production are analyzed based on process simulation in terms of their energy demand for CCU and compliance with current EU legislation on renewable fuels over the service life of a CCU plant.