Incineration Industry Research Articles

Selection of an oxygen injector for waste oxygen enrichment incineration with dual carbon targets

Abstract Waste incineration is one of the most effective means of achieving harmlessness, minimization, and resource utilization. As environmental problems become more and more prominent, the more stringent environmental standards will greatly limit the development of conventional waste incineration technology. Therefore, the development of a new type of clean and efficient waste incineration technology will be the inevitable development trend of the waste incineration industry. Oxygen-enriched injector sizing study was carried out based on Computational Fluid Dynamics (CFD) techniques for the oxygen-enriched incineration technology used in waste grate incinerators. The application of CFD method is applied to different types of oxygen injection device velocity fields, temperature fields, concentration fields, etc. The results show that the ring-type oxygen injector can achieve a good mixing effect, and the resistance pressure drop is minimized, which is better than the nozzle-type oxygen injector to meet the actual needs of the project.

Impact of environmental regulation on government subsides of public-private partnership waste-to-energy incineration projects: evidence from 66 cities in China

Introduction: Environmental regulation, as a vital component of public regulation in China, plays a crucial role in coordinating regional eco-efficiency, while the traditional hypothesis, Porter hypothesis, and uncertainty hypothesis offer three different perspectives for understanding the relationship between industry performance and environmental regulations.Methods: Based on the assumption of industry heterogeneity, 81 public-private partnership (PPP) waste-to-energy (WTE) incineration projects are analyzed using panel data from 66 cities within China during the period from 2013 to 2017 with the aims to reveal the underlying mechanism behind environmental regulation and the government subsides of public-private partnership waste-to-energy incineration projects by using multiple regression modeling.Results: The results show that the impact of environmental regulation on government subsides of PPP WTE projects has demonstrated an “Inverted-U”-shaped relationship with an inflection point, of which an increase in environmental regulation is positively correlated with an increase in subsidies at first then a negative correlation developing later.Discussion: The findings are significant in setting flexible environmental regulations according to the needs of regional economic and social development. In addition, they also supply a theoretical reference for promoting the WTE incineration industry’s sustainable and healthy development.

Low permeability sealing materials based on sewage, digestate and incineration industrial by-products in the final landfill cover system

This study explores repurposing municipal solid waste from the sewage, digestate, and incineration industries as landfill-sealing materials, aligning with circular economy principles. The main materials include digested sewage sludge (DSS), pretreated digested sewage sludge (PDSS), and digestate sludge (DS), with biomass bottom ash (BBA) and Al-anodizing waste (AAW) introduced as additives, complemented by 1.5 wt% water glass to enhance the sealing performance. The research evaluates the characteristics of the various treated and sourced sludges and additives, assessing their influence on water permeability, reaction products and the environmental consequences. Results demonstrate the achievement of low permeability in the sludge-based sealing materials, with optimal performance observed in the specimens prepared with DSS and AAW (k value = 3.78 ×10−12 m/s). Thermal Pressure Hydrolysis pre-treatment in sewage plants reduces the organic content in PDSS, resulting in a slight increase in permeability. DS-based specimens exhibit higher permeability due to their relatively lower organic content in DS. Gypsum is the primary reaction product attributed to leachable sulphate in BBA and AAW. Water glass addition in BBA-modified specimens promotes silica gel formation, while AAW effectively reduces matrix permeability as an externally added gel-like substance. Additionally, heavy metals (As, Pb and Cr) derived from the by-products are effectively immobilized in the sealing materials owning to the coagulation effect of organic matter in the sludge and sulphates in the products. Overall, this novel approach to landfill sealing materials exhibits promising applications in the Netherlands, offering cost savings and reduced environmental impact by recycling industrial by-products.

Health effects of future dioxins emission mitigation from Chinese municipal solid waste incinerators

Dioxins (including 2,3,7,8-tetrachlorodibenzo-p-dioxin, as Group 1 Carcinogen) in the atmosphere mainly originate from incomplete combustion during municipal solid waste (MSW) incineration. To significantly reduce dioxins emission from the MSW incineration industry, China has promulgated a set of ambitious plans regulating MSW-related pollution; however, the emission reduction potentials and concomitant environmental and health impacts associated with the implementation of these programs on a national scale remain unknown. Here, we use real measurements from official environmental impact assessment systems and continuous emissions monitoring systems (covering 96.6% of national MSW incinerators) to estimate unit-level dioxins emission and concomitant environmental and health impacts. We find that in 2018, 99.3% and 66.7% of Chinese incinerators met such concentration and temperature standards, respectively, controlling the total emissions to 19.6 g toxic equivalency quantity and maintaining carcinogenic and noncarcinogenic risks significantly below safety levels nationwide. Fully achieving both current standards and future regulations will reduce emissions and health risks by 67.7% and 62.6%, respectively, with waste sorting program contributing the majority. This study reveals substantial benefits from curbing MSW-related dioxins pollution and underscores the promise of ongoing management.

Quantitative risk assessment of occupational exposure to PCDD/Fs in the waste incineration industry

Objective: To analyze the level of PCDD/Fs exposure of occupational workers in the waste incineration industry and explore the risk of occupational exposure. Methods: In September 2021, literature on environmental PCDD/Fs exposure in waste incineration plants published from the establishment of the database to February 10, 2021 was retrieved from CNKI database. A total of 1365 literatures were retrieved, and 7 met the criteria for inclusion. The US Environmental Protection Agency (EPA) inhalation risk model was used to assess and analyze carcinogenic and non-carcinogenic risks of PCDD/Fs exposure among occupational workers in the waste incineration industry. Results: A total of 86 sampling sites were included in incineration plants in 7 regions. The study of Wuhan area showed that the concentration of working environment near the waste incinerator in the same factory was the highest, followed by the rest and office area in the factory. The concentration of PCDD/Fs in waste incinerators was the highest in Southwest China (4880.00-24880.00 pg TEQ/m(3)), and the lowest in Shenzhen (0.02-0.44 pg TEQ/m(3)). According to the cancer risk assessment, with the increase of exposure years, the risk of cancer increased. The highest risk of cancer was found in the waste incineration plants in Southwest China. When the exposure period was 1 year, the risk was moderate (22.40×10(-6)-114.20×10(-6)). When the exposure time was more than 5 years, the risk of cancer was high. In Jinan, workers working near the incinerator had a moderate risk of cancer after five years of exposure. In Zhejiang, workers were at medium risk of cancer after exposure for more than 20 years. Workers in Wuhan, Shanghai, Zhejiang Province, Shenzhen and the Pearl River Delta were still at low risk of cancer after 40 years of occupational exposure. HQ>1 of workers working near the waste incinerators in Jinan, Zhejiang Province and Southwest China, and the qualitative evaluation results showed that the non-carcinogenic risk was unacceptable. Conclusion: There are great differences in PCDD/Fs of occupational exposure in waste incineration industry, and the occupational exposure exceeding the occupational exposure limit has higher carcinogenic and non carcinogenic risks.

Fly ash treatment by desalination couples with solidification of heavy metals

Fly ash is the solid by-product of waste incineration. It contains high content of soluble salts and heavy metals, which causes difficulty in treatment. In this study, desalination coupled with heavy metal solidification is investigated for the treatment of fly ash from hazardous waste incineration. The distribution of salt and heavy metal and the leaching toxicity of heavy metal were detected. Sintering not only reduces the bulk density of fly ash but also can reduce heavy metal leaching toxicity. For instance, the soluble heavy metal was reduced by 95.4% after 700 °C sintering. The bulk density of fly ash increases from 0.295 g/cm3 to 1.046 g/cm3 after treatment, which significantly save the space of landfill. Meanwhile, the treated ash can meet the leaching limit of heavy metals for the flexible landfill in China. This research is meaningful for fly ash treatment industry and the sustainable development of waste incineration industry.

Air pollutant emissions and reduction potentials from municipal solid waste incineration in China

China fully implemented the new emission standards in 2016 to further reduce the emissions of air pollutants from the municipal solid waste (MSW) incineration industry; however, the implementation effect of the new standards remains unknown. This study developed the first nationwide air pollutant emission inventory of MSW incineration plants in China based on the measured concentration data from China's continuous emissions monitoring systems (CEMS) network, and activity level data from the China Urban Construction Statistical Yearbook, to evaluate the effectiveness of implementing the new emission standards and estimate the future reduction potentials. Our results demonstrated that the overall standard-reaching proportions of particulate matter (PM), sulfur dioxide (SO2), nitrogen oxide (NOX), hydrogen chloride (HCl) and carbon monoxide (CO) were 98.8%, 99.3%, 99.4%, 99.4% and 97.6%, respectively, by comparing with the corresponding concentration limits of new emission standards. The total emissions of PM, SO2, NOX, HCl and CO from 412 MSW incineration plants in 2019 were 1.9, 6.2, 50.8, 4.3 and 6.6 kt yr−1, respectively, which is 33.6–75.8% lower than those in 2015, mainly due to the sharp decrease in emission factors. Pollutant emission hotspots were mainly concentrated in eastern and central and southern regions with large populations and well-developed economies. The analysis of future scenario results shows that despite the continuous increase of MSW incineration amount in the future, if the government strengthens pollutant emission standards and comprehensively implements waste sorting, total emissions and emission factors of air pollutants could be further reduced by 25.8–72.7% and 59.8–81.2%, respectively, by 2050. These findings provide helpful insights into future policymaking and technology selection for China and other countries seeking to reduce pollutant emissions from the MSW incineration industry.

Structural Optimization of Ring Type Oxygen Injector for Waste Incineration Research

Waste incineration is one of the most effective means to achieve harmless, reduction and resource recovery. As environmental problems become more and more prominent, increasingly stringent environmental standards will greatly limit the development of conventional waste incineration technology, therefore, the development of a new clean and efficient waste incineration technology will be the inevitable development trend of the waste incineration industry. Based on the computational fluid dynamics (CFD) technology, the structural optimization of the ring oxygen injector used in the oxygen-enriched incineration technology of the waste grate incinerator is investigated. The results show that the oxygen injection ring diameter is 0.7071D, the air duct length is 1.4D, and the oxygen injection ring outer hole is 0.28d and inner hole is 0.4d.

Spatiotemporal Distributions and Source Apportionment of PM2.5‐Bound Antimony in Beijing, China

AbstractAntimony (Sb) is a toxic heavy metal, and PM2.5‐bound Sb (SbPM2.5) in the air impacts human health via inhalation pathways. In this study, we analyzed multiyear measurements of ambient SbPM2.5 in Beijing to characterize its spatiotemporal distributions, identify main sources, and predict future trends. The results show that ambient SbPM2.5 has been decreasing with fluctuations from 2005 to 2012 and decreased rapidly after 2013, which was likely a result of the government's enhanced air pollution control plan that targeted main sources of industrial Sb. Across the city, average SbPM2.5 concentrations were relatively higher at nonemission locomotive traffic sampling sites and in densely populated areas (9.45–19.45 ng/m3) and lower in background areas (0.6–0.9 ng/m3). Regional‐scale emissions and local human activities both affected the spatial distributions of SbPM2.5. Notably, SbPM2.5 concentration increased by 58.3% from 2006 to 2013 in one suburban background area, indicating the changing emission distributions and intensities over the study period. A neural network model was developed and tested to predict future SbPM2.5 levels, results from which showed that with simulated massive reductions in coal supplies and a rapid boom in the waste incineration industry, SbPM2.5 concentration would vary in a smaller range (from 4.08 to 4.38 ng/m3) over the next decade as compared to the observed range during 2011–2018 (19.0–5.44 ng/m3). The impact of the continued expansion of the waste incineration industry on SbPM2.5 pollution needs to be considered in future emission control policies.

Model framework to quantify the effectiveness of garbage classification in reducing dioxin emissions

Although waste incineration is a promising disposal method, it produces unwanted combustion by-products, such as toxic dioxins, that can be unintentionally emitted. Kitchen scraps can result in incomplete combustion of waste, which accelerates the formation of dioxins, especially for the small-sized incinerators without identical operating temperature. Consequently, garbage classification before waste incineration is critical for dioxin control in the small-sized waste incineration industries. To date, the influence of garbage classification on dioxin emissions has not been quantified. In this study, a model framework integrating the grey prediction model and autoregressive prediction model was established and used to predict future dioxin emissions from small-sized waste incineration. If garbage classification is ideally strictly implemented, annual dioxin emissions could be reduced by up to 1697 g TEQ over the next 10 years. Garbage classification reduced emissions by about 30.7% compared with incineration of mixed municipal solid waste without classification (5534 g TEQ over the next 10 years). The established model framework can effectively assess the influence of garbage classification on dioxin emissions from waste incineration, which could facilitate the widespread adoption of garbage classification.

Determination of solid-phase reaction mechanism and chlorine migration behavior of co-pyrolyzing PVC[sbnd]CaCO3 based polymer using temperature-dependent FTIR and XRD analysis

This paper investigates the pyrolysis of outer sheath polymer of a PVCCaCO3 based cable. TG-DSC-MS, temperature-dependent FTIR, XRD and XPS experiments were conducted to study the pyrolysis characteristics and chlorine migration law for solid products. The results show that the pyrolysis can be divided into three stages induced by co-pyrolysis of PVC and CaCO3. In the first stage, the PVC dehydrohalogenation takes place producing the majority of HCl. CaCO3 does not participate in the solid-phase reaction. In the second stage, the cyclization of olefin chains occurs with a low HCl production. The CaCO3 reacts under high temperature, absorbing HCl in crystal lattice producing CaCl2 and CO2. In the third stage, the CaCO3 continues consuming HCl, meanwhile it starts pyrolyzing above 800 °C, generating CaO and CO2. The final residue mainly consists of CaCl2 and CaO and the organic Cl is ignorable. As the Cl-capturing reactions occur under high temperature with a low HCl production, the efficiency of CaCO3 reducing HCl is low, which explains the findings in previous study. This paper reveals the solid-phase reaction scheme and the law of Cl migration of the PVCCaCO3 based polymer pyrolysis, providing fundamentals for modeling and contributing to the understanding of cable pyrolysis for incineration industry.

Catalytic removal of NO and chlorobenzene over Ce-Mn-W-Zr-Ox/TiO2: Performance study of hollow spheres effect

Co-catalytic removal of multiple pollutants was able to reduce operating costs of enterprises, which was the main development direction for the waste incineration industry. In this work, the influence of hollow structure on the catalytic performance was investigated. The coexistence of anatase and rutile phases in the hollow structure accelerated the activation of reaction molecules on the catalyst surface and promoted the improvement of reaction activity. Furthermore, the confinement effect of the hollow structure may promote the adsorption of reaction molecules inside the sphere, and prolong the reaction time of the molecules at the active site of the catalyst, thereby promoting the progress of the reaction. It was the excellent redox performance and fast oxygen migration ability of hollow structure that made CMWZ/H-TiO2 had excellent performance in co-catalytic removal of NO and chlorobenzene. Finally, NH4+ and –NH2 were the main ammonia species in the SCR reaction, and –NO2 was the main NO adsorption species, so the reaction of SCR on the CMWZ/H-TiO2 catalyst followed the L-H mechanism. For the degradation of chlorobenzene, the main intermediate products at low temperature were phenolic species and maleate species. At high temperature, the intermediate products of chlorobenzene were mainly maleate species, bidentate carbonate species and carbonate species.

Overview of public-private partnerships in the waste-to-energy incineration industry in China: Status, opportunities, and challenges

To accommodate the rapidly increasing amount of municipal solid waste (MSW) sustainably and effectively, public-private partnership (PPP) waste-to-energy (WTE) incineration has achieved rapid growth in China. This study provides an insight into current practice and identifies key opportunities and major challenges in the further development of PPP implemented in China's WTE incineration industry. The results show that the public-private-partnership market is currently under a period of rapid expansion, with a large number of well-funded and highly professional public-private partnership suppliers emerging in recent decades, but at a level of market concentration that is significantly lower than in mature markets such as in the United States and Japan. Meanwhile, excellent market potential and preferential policies, as well as booming technological innovations, provide sufficient motivation for further development. However, the quality and quantity of municipal solid waste supplied, emerging public opposition, policy changes and the development dilemmas involved are major challenges to the sustainable and healthy development of the waste-to-energy incineration industry in China. These findings make strong contributions and have both theoretical and practical implications for researchers and practitioners, including policymakers and incineration professionals in the PPP WTE incineration industry.

Technical and Environmental Efficiency of MSW Incineration Industry in Korea-A Stochastic Frontier Production Function Analysis

This article analyzes the technical and environmental efficiencies of the MSW incineration industry across 16 cities and provinces in South Korea. The empirical results show significant variations in environmental efficiency, which range from 0.275 to 0.989 with a mean value of 0.912. The Gyeonggi-do region is the most environmentally efficient, while Busan is the least efficient. Moreover, some cities, such as Busan and Daegu, exhibit high technical efficiencies yet have dramatically low environmental efficiencies. Similarly, Seoul and Gwangju perform excellently in terms of environmental efficiency but have the lowest technical efficiencies. The output elasticity was calculated for each input, and the average output elasticity for CO2 is 0.090. Finally, the scale elasticity in the waste incineration industry was lower than 1.

Technical and economic analysis of energy generation from waste incineration in Mexico

In this paper we evaluated the feasibility of energy generation by incineration of waste in Mexico. The population of Mexico was split into six population-size classes, each one associated to a waste generation index. The total amount of waste and the lower calorific values were used to estimate the power and energy resulting from each size class. The economic feasibility was evaluated using the Levelized Cost of Energy (LCOE), Net Present Value (NPV) and Internal Rate of Return (IRR). For populations up to 3 million inhabitants the incineration of waste resulted in 58.9 MW. The total energy generation resulted in 11,681.64 GWh contributing to 4.3% of the national demand. The NPV and IRR showed negative values per lower sizes of population and the LCOE resulted in higher values than other energy sources. A sensitivity analysis was conducted, addressing specific elements of the analysis to show how the project can become economically feasible when adjusting investment, O&M and sales tariff. This research provides evidence on how the Waste-To-Energy (WTE) incineration industry is feasible in Mexico and provides significant benefits, not only by strengthening the renewable energy sector but also by significantly improving the waste management system.

Leader-follower optimized approach for carbon-economy equilibrium in the municipal solid waste (MSW) incineration industry.

Municipal solid waste (MSW) incineration contributes significantly to carbon emissions, and has become a serious problem in China, which has seen an exponential rise in waste over the last twenty years due to rapid urbanization and the associated consumer economy growth. To tackle this issue, this paper develops a leader-follower optimized approach for economic and environmental equilibrium in incineration power plants that includes a carbon allowance allocation scheme (IPP-CAAS) under combustion and pollutant limitations. In the leader-follower (bi-level) game, the regional authority on the upper level determines the carbon allocations and environmental targets and the IPPs on the lower level develop schemes to maximize revenue under the upper-level restrictions. By employing uncertain parameters for the carbon and power conversion fluctuations, the approach is able to more accurately depict the industry characteristics of waste incineration process in this carbon-economy balance problem. The robustness and practicality of the proposed methodology was then validated through a case study. Scenario analysis under different political parameters indicates that the proposed methodology can assist the authorities to achieve carbon-economy trade-off and under serious carbon-control situations, encourage the IPPs to reduce their blended coal ratios, and invest in low-carbon incineration technology. Managerial insights on further industrial developments are also given for the authority and relevant practitioners.

Current Status of Technology and Standards of domestic Solid Waste Incineration in China

This paper sorts and analyzes current technologies and standards, as well as existing problems and demands in the domestic solid waste incineration industry in China, in order to further promote the establishment of domestic solid waste incineration standard system in China, standardize key technologies, devices and processes of efficient waste incineration, and promote the manufactry and utilization of advanced equipment, thus providing solid technical support and guarantee for the enhancement of overall performance level and pollutant up-to-standard emission of domestic solid waste incineration industry in China.

Catalytic removal of NO and dioxins over W-Zr-Ox/Ti-Ce-Mn-Ox from flue gas: Performance and mechanism study

Co-catalytic removal of multiple pollutants was able to reduce operating costs of enterprises, which was the main development direction for the waste incineration industry. In this work, series W-Zr-Ox/Ti-Ce-Mn-Ox (WZ/TCM) catalysts were designed to investigate independent NH3-SCR, dioxins oxidation and co-catalytic removal of NO and chlorobenzene (CB, the substitute of dioxins). The W-Zr-Ox mainly provided solid super acids; CeO2 and MnO2 enhanced the redox performance; and TiO2 provided a large specific surface area. All these factors guaranteed the excellent performance of WZ/TCM catalyst. The NO conversion of WZ/TCM reached 100 %, and the oxidation activity of CB was also higher than 85 % at 350–500 ℃. Meanwhile, the WZ/TCM had high N2 selectivity and excellent resistances to sulfur and water. In situ infrared diffuse reflectance spectra confirmed that ammonia gas mainly adsorbed on the Lewis acidic sites of the WZ/TCM catalyst and participated in the SCR reaction at low temperature. The ammonia species (NH4+) at the Brønsted sites participated in the reaction at high temperature. Furthermore, the chlorine atom on the chlorobenzene molecule was mainly removed to reduce toxicity when the oxidation of CB was at low temperature, which was deeply oxidized and had a variety of intermediate products at high temperature.

Inventory of Polychlorinated Naphthalene Emissions from Waste Incineration and Metallurgical Sources in China.

Polychlorinated naphthalenes (PCNs) are highly toxic persistent organic pollutants (POPs) that are a relatively new addition to the Stockholm Convention as of 2015. The levels of unintentional emissions of PCNs from important industrial thermal sources on national scales are unclear but are important for understanding potential human exposure. In this study, an inventory was compiled of PCN emissions from priority industrial sources of unintentional POPs in China. Estimated emissions from four typical POP sources in the reference year (2014) in China were 511.6 kg by mass and 7650.8 mg of toxic equivalent. Waste incineration, secondary nonferrous smelting, electric arc furnace steelmaking, and iron ore sintering plants contributed 38.8, 15.4, 29.2, and 16.6%, respectively, to the total emissions. The Eastern Seaboard of China and the Hebei region in North China, which have intensive industrial activity and high population densities, were dominant contributors of PCNs. Only 18.6% of the counties where waste incineration plants were located emitted PCNs at a level higher than 1.00 × 10-1 mg of toxic equivalent, whereas 80% of the counties where metallurgical plants were located emitted PCNs at this level. These results indicate effective implementation of POP control in the waste incineration industry in China. This study clarifies the unintentionally emission levels of PCNs in China and provides important information for strategy development to control source emissions.

Determining critical risk factors affecting public‐private partnership waste‐to‐energy incineration projects in China

AbstractAs the most effective way to manage the surge in municipal solid waste (MSW) and global energy issues, waste‐to‐energy (WTE) incineration plants have been actively promoted by the Chinese government, and the public‐private partnership (PPP) procurement model is widely used to improve management efficiency. However, risk events have occurred frequently in this industry due to a lack of practice experience and to poor risk management. To investigate the potential risk factors in PPP WTE incineration projects in China, this paper aims to identify critical risk factors by assessing their severity and occurrence probability. Opinions of industry experts were collected via an empirical questionnaire survey. The respondents were invited to rate a total of 18 risk factors that impact the success of PPP WTE projects as gleaned from previous research. The overall results ranked risk factors based on risk impact and showed that public opposition, government decision making, defective legal and regulatory systems, environmental pollution, lack of supporting infrastructure, and government credit are the top six risk factors affecting the sustainable development of PPP WTE incineration projects. In addition, the causes and consequences of each critical risk factor are comprehensively analyzed. Lastly, practical and managerial implications are analyzed in terms of their management of these critical risks. The originality of this research lies in thoroughly identifying potential implicit risk factors according to the current social background using an empirical questionnaire survey based on case study findings. The results of this study are expected to improve risk management and facilitate the sustainable development of the PPP WTE incineration industry in China.