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The selection of refractory bricks significantly impacts the operational performance of brick structures in high-temperature environments. In this study, a coupled thermal stress model of a refractory brick structure was established and validated by means of thermal expansion experiments. This paper innovatively combined the brick number, brick thickness, and brick material to investigate their influence on brick structural performance. The results indicated that the influence of the brick number on the temperature was less significant than that of brick thickness. However, the brick number had a greater effect on vertical displacement and principal compressive stress than brick thickness, with the maximum differences being 342.3% and 28.9%. Compared to brick thickness, brick material had a more significant effect on vertical displacement and principal compressive stress, with the maximum differences being 77.1% and 67.4%. Additionally, the influence of brick material properties on vertical displacement and principal compressive stress was greater than that of the brick number, with the maximum differences being 77.6% and 65%. Therefore, when selecting refractory bricks, it is advisable to consider the brick material first, the brick number second, and the brick thickness last. This study offers theoretical guidance for refractory brick structure design and material selection in high-temperature applications. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Engineering (17264073) is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This research analyses a Brayton cycle power plant that utilizes waste as its energy source and an organic Rankine cycle. Integrating the Brayton cycle and the ORC, powered by incinerating municipal waste, is innovative. In this research, for the first time, a four-purpose survey was conducted on the waste incinerator power plant with Brayton cycle and gas turbine, and then it was carried out to optimize it. This study takes a significant step forward in advancing this technology through optimization. The energy and exergy analysis method was used to maximize the power of the power plant, the CEA method was used for economic analysis, and the genetic algorithm was used for optimization. The first step involves modeling the desired power plant, followed by calculations of exergy destruction, environmental cost, and construction cost. Subsequently, the system's exergy-economic and exergyenvironmental performance is evaluated. Finally, the system optimizes power generation while minimizing pollution and cost. The results indicate that the power plant construction is not economically viable without considering its environmental benefits. The exergy destruction is calculated to be 95.75 $ per hour for a plant with 4530 kW output power. With optimization, the exergy saving is 34.19%, and the total activity costs amount to 174.5 USD/GJ. [ABSTRACT FROM AUTHOR]

Sustainable development is an integral part of the modern world. However, sustainable development is impossible without rational, environmentally and economically efficient use of resources. In the process of construction and operation of underground structures (mines, subway stations, subway parking lots, etc.) there are many factors that cannot be taken into account at the design stage. These factors have a negative impact on the durability of use, economic profitability of operation, etc. In this paper, the authors used the theory of system analysis to form and optimize the factors affecting underground structures. They identify the relevant regularities and interrelationships. They determine the list of the most important factors based on the peculiarities of a particular object of study. They build a conceptual and then a mathematical model. In the practical part of the study, the authors model the temperature field formed in a horizontal mine. They compared the obtained results with the modeling results presented by others and showed the effectiveness of the proposed methodology. A distinctive feature of this work is the proposed methodology for assessing the factors affecting sustainable development. This methodology is universal and can be applied to assess the sustainable development of any management object. [ABSTRACT FROM AUTHOR]

This paper presents a numerical simulation and structural optimization study of the combustion process within the grate and boiler furnace of a 750 t/d waste incineration. The study focuses on adjusting the secondary air velocity, secondary air inclination angle, and the arrangement of secondary air nozzles. These adjustments aim to optimize parameters such as the temperature field, pollutant emission, flow field, particle residence time, and filling degree. The findings demonstrate that high-temperature zones, which lead to slagging problems, are likely to form beneath the front arch. The combustibles inside the furnace are thoroughly burnt, reflecting efficient combustion. The concentration of NOx in the flue gas at the furnace outlet generally ranges between 170 and 200 ppm. Optimal operating conditions are identified as a secondary air inclination angle of 20° with an air velocity of 55 m/s, and an angle of 30° with an air velocity of 55 m/s and 65 m/s, in conjunction with a relative arrangement of the nozzles. Under these conditions, the incineration furnace achieves its best operational state. [ABSTRACT FROM AUTHOR]

Investment in science, technologies, and infrastructures has been a critical aspect of China's development strategy since the early 2000s. China's national policies designated waste-to-energy (WtE) incinerators as the dominant end-of-life technology to bring about a form of modern and sustainable waste treatment that can turn waste into energy while eliminating pollution. Amid rising citizen skepticism over the safety and efficacy of this technology in China and elsewhere, this article examines the genre of the orchestrated waste tour, which seeks to place the public as witnesses to state performances of technological improvement. Tours to waste facilities illuminate the generic conventions and strategies that China's late-socialist mode of green techno-scientific governance relied on to legitimize its achievement of environmental improvement. Tours did not produce passive observers. Through an in-depth discussion of a waste tour in Guangzhou, this paper documents that opportunities for firsthand encounters of WtE incinerators provided a forum for those suspicious of the state's claims of techno-science to form counternarratives. [ABSTRACT FROM AUTHOR]

Background: Metal exposure during medical waste collection, handling, and burning poses a skin danger to individuals working in the waste incineration industry. Medical waste incineration ash contains about 30 distinct metals, the majority of which are toxic to humans. This study attempts for improving the health of workers at medical waste incinerators through identifying some occupational morbidities among workers at medical waste incinerators. Methods: A comparative cross-sectional study was conducted at medical waste incinerators at Sharkia governorate. The target population composed of exposed group (n=56), including workers at medical waste incinerators who are involved in all steps of handling, management and processing of medical waste and non-exposed group (n=56), including administrative employees working at Faculty of Medicine, Zagazig University. Pre-constructed questionnaire was filled by all participants for their occupational history and dermatological presentations. Results: A statistically significant increase in frequency of burn (OR=5.34), urticaria (OR=7), exposure to sharp injuries (OR=85), pruritis and fatigue among exposed compared to non-exposed group. Also, a statistically significant increase in dermatological morbidities were found among workers who had previous job & not wearing protective personal equipment (PPE) compared to workers without (p=0.01). Conclusion: It can be concluded from the results of the study that incinerator workers at Sharkia governorate are at risk for dermatological disorders and sharp injuries who pose them to risk of Hepatitis B (HBV) and Hepatitis C (HCV) infection. [ABSTRACT FROM AUTHOR]

This research examines the possibility of the washing process as a supplementary operation after extensive extended physical separation sequences for processed incinerator bottom ash (pr.IBA), which is the mineral fraction resulting from conventional separation operation of municipal solid waste (MSW) incinerator bottom ash (IBA) in Germany. Citric acid is employed as the only primary treatment agent in several variations of parameter combinations. It includes the type of solvent, washing duration, acid concentration, liquid-to-solid ratio, and introduction of external agitation (stirring and heating). The analysis results revealed that the concentration of copper, zinc, and manganese in the mineral phase of pr.IBA can be reduced by the citric acid washing process. The most significant change is observed in the zinc content, where a reduction of up to 50% is successfully achieved. In contrast, the silicon concentration is relatively unaffected during citric acid washing, but a concentration decrease is detected for calcium. The aluminum and iron contents in the studied fraction of pr.IBA are also soluble in citric acid solution, although the rates are expected to be exceptionally slow. In this instance, stirring and heating over a prolonged washing duration are necessary before a decrease in their concentration can eventually occur. [ABSTRACT FROM AUTHOR]

• We developed an algorithm for predicting heating value and composition of waste. • Measurement points were suggested for optimal waste management. • Heating value and composition of waste were derived. • Operating strategy is proposed to improve energy recovery efficiency. • This methodology can contribute to optimal operation of waste incinerator plants. The heating value and composition of waste are crucial operational variables for understanding waste incinerators behavior and optimizing their operation. However, because the heating value and composition of waste are highly variable, their prediction in waste incineration plants is difficult. To overcome this issue, this study developed a novel method to derive heating value and composition waste via a reverse calculation algorithm using operating data and physics-based model. In addition, a process simulation model was developed to predict the performance of waste incinerator systems. We derived heating values and compositions of waste in the target incinerator using the supposed method and proposed an operating strategy to improve the energy recovery efficiency of the waste incinerator through the process simulation model. The energy recovery efficiency increased by approximately 10 % relative to that of the existing incinerator operation. The methodology developed in this study can be applied to various incinerator systems. Our study findings contribute to establishing an optimal operation of a waste incinerator by calculating the heating value and composition of waste. [ABSTRACT FROM AUTHOR]

Copyright of International Journal of Professional Business Review (JPBReview) is the property of Open Access Publications LLC and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The safe and sustainable management of biomedical waste is a social and legal responsibility of all people supporting and financing health-care activities. Appropriate BMW management (BMWM) is mandatory for protecting the health of human beings. This article provides a detailed information pertaining to the biomedical waste management system functioning within the state of Kerala. In Kerala there are two CBWTF-IMAIMAGE and KEIL. The modern IMA-IMAGE system is responsible for the management of about 82% of the biomedical wastes generated from the health care institutions within the state of Kerala. The biomedical wastes generated within the Health care institutions is appropriately collected, transported and treated by the CBWTF thereby creating a safe environment for the public and the health care workers. [ABSTRACT FROM AUTHOR]

The priority during an emergency, regardless of the type, is to rescue as many lives as possible. Field hospitals are usually installed to provide the primary relief to the affected population when hospitals are compromised or absent. There are several sanitary units worldwide ready to be transported to disaster areas. An average field hospital is equipped with an operating room, laboratory, and radiological equipment, but it does not include a unit for the infectious hospital solid waste treatment, which results in improper management with high infection risks and emissions due to incorrect operations (e.g., open incineration). Therefore, the present study identified two market-available solutions (an incinerator and a sterilizer) designed to be transported even under the challenging conditions typical of disasters and are suitable for treating infectious waste. The systems were assessed by a life cycle assessment (LCA), proving an emission savings >90% (considering all impact categories) using the sterilization system. The avoided combustion allows to halve the effect on climate change due to a portable incinerator. This study supplies interesting food for thought for the emergency managers, proving the possibility of integrating the sustainability also in the planning of the response to catastrophic events. [ABSTRACT FROM AUTHOR]

This research introduces selective milling as a reliable and effective initial concentration process to enable efficient separation and ensure high recovery rates of valuable and critical materials (minerals and metals) from processed incinerator bottom ash (pr.IBA), a treated mineral fraction originating from the conventional municipal solid waste (MSW) incinerator bottom ash (IBA) processing steps. Four different types of pr.IBA (each sample weighing up to three tons) were selectively milled using a demonstration-scale vertical roller mill to produce three distinct products: fine, middle, and coarse fractions. Chemical analysis demonstrated that a concentration step after selective milling could be reliably achieved regardless of the variation in the sources and qualities of the input materials. Specifically, calcium-containing compounds can be enriched in the fine fraction, potentially containing Ca2SiO4, CaSO4, and CaCO3. Complementary to its particle size equivalent to the raw mix, this calcium segregation could be valuable as an alternative material in cement clinker production. Conversely, the segregation of metal-bearing substances, particularly iron and copper, was detected in the coarse fraction. Such segregation is comparable to specific ore grades and enhances the possibility of metal recovery from pr.IBA. [ABSTRACT FROM AUTHOR]

Identifying the ash accumulation generated on the water-cooled walls of the waste incinerator is essential for the cleanup by the robotic arm. This paper improves a new algorithm based on YOLOv8n, which can identify the ash accumulation position on the water-cooled wall quickly and accurately. Firstly, the multi-scale fusion image enhancement algorithm is used to improve the sharpness and contrast of the image and enrich the details of the image. Secondly, the backbone feature extraction network of YOLOv8n is replaced by Mobilenetv3 network, which reduces the parameters in the model greatly. Finally, this paper improves a new attention mechanism AWGAM (Add Weight Global Attention Mechanism) based on GAM (Global Attention Mechanism), which can better integrate the feature information between different dimensions and improve the learning ability of the model. AWGAM is added to the backbone of the model. The experimental results show that compared with the original YOLOv8n model, the improved YOLOv8n model has 59.9% fewer parameters, 4.4% higher precision, 8.8% higher recall, 3.2% higher mAP50 (mean Average Precision) and 8.8% higher mAP50-95. This model has made remarkable progress on the basis of the original algorithm, and has strong competitiveness compared with other advanced target detection models. The lightweight and high accuracy of ash accumulation detection offered by the proposed model presents promising applications in ash accumulation detection tasks of water-cooled walls. [ABSTRACT FROM AUTHOR]

The waste management issue in developing countries, particularly in Indonesia, remains uncontrolled and is urgent to address. This problem is significantly tied to the issue of resource scarcity and global climate change. Various policies have been formulated, both globally and nationally, to resolve this issue. Makassar City is one of the cities the government should target to achieve the goal of converting waste into energy by 2025. This study focuses on the environmental impact of various scenarios on waste-to-energy potential using life cycle assessment (LCA) in Makassar City. The waste management strategy in this study uses five scenarios, comparing incinerators generating electricity, landfills with gas, and composting. The results showed that scenario 5, which has a low environmental impact, consists of 10% composting, 45% incineration, and 45% landfill gas (LFG). Incineration can reduce 45% of solid waste disposal (SWD) and produce 1.45 E + 08 kg/year of CO2 emissions. The waste-to-energy (WtE) scenario model significantly reduces the environmental impact, especially the concentration of greenhouse gases (GHGs) in the atmosphere. The role of incinerators in the environment is not only to reduce the volume of SWD per year but also to provide a new source of energy. The LFG collector plays a crucial role in reducing the concentration of CH4 in the atmosphere due to its facility for capturing CH4 gas. [ABSTRACT FROM AUTHOR]

• Gas-solid coupling corrosion of steels under Cl-containing environment is studied. • The gas–solid coupling corrosion is much stronger than the independent gas corrosion. • Two layers of corrosion products with huge different characteristics are observed. • FeCl 2 &CrCl 2 amalgamate with the chloride salts form a low-melting liquid phase layer. • The O and Cl elements react with the metal substrate through the molten layer. The fast development of the waste incineration industry requires deeper insights into heating surface corrosion behavior at higher operating parameters with complex corrosion sources. This research investigates the corrosion behaviors of three types of plates, namely SA210-C, TP310, and 12CrMoV, when subjected to simulated flue gas and fly ash deposition simultaneously at temperatures ranging from 500℃ to 620℃. The results indicate that the weight loss due to coupling corrosion was 2.5 to 84.5 times higher than that of gas-phase corrosion under the same operating conditions. Among the three stainless-steels, TP310 demonstrates superior corrosion resistance. It is worth noting that, under the gas–solid coupling corrosion conditions, we observed a distinct two-layer structure of corrosion products. Despite the fly ash simulants detaching over time, the two-layer structure remained unchanged. Based on the theory of eutectic molten salt formation, we propose that alkali metal chlorides only initiate the formation of the molten layer in the initial stage of corrosion. Furthermore, we offer additional suggestions for the mechanism of sustaining the molten layer in the absence of alkali metal chlorides. [ABSTRACT FROM AUTHOR]

Copyright of Petroleum Refinery Engineering is the property of Petroleum Refinery Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

AbstractGarbage incineration power generation is utilized to dispose of multi-source organic solid waste. This work constructed a mathematical model for a 750 t/d garbage incinerator to reveal the coupled response between the boiler and furnace sides. Field experiments validated the model, exploring various operating conditions including different loads, fuel blending ratios, primary air, and internal flue gas recirculation (IGR) air flow rates. Increasing the load by 9.1% raised furnace heat exchange by 4.0% but reduced economizer heat exchange by 19.0%. Introducing waste cloth strips and paper mill waste enhanced furnace water-cooled wall heat transfer but reduced economizer heat exchange. A 10.8% rise in primary air flow increased superheater heat exchange by 7.8%. Similarly, a 21.3% rise in IGR air flow increased economizer heat exchange by 9.0%. The temperature rise and enthalpy rise in the superheater were higher when the low calorific value of the fuel was higher. Increasing primary air velocity enhanced heat transfer, raising the outlet temperature of the medium-temperature superheater, necessitating an increase in secondary water spray to adjust the outlet temperature of the high-temperature superheater. This work provides guidance for the design and practical operation of multi-source solid waste incinerators. [ABSTRACT FROM AUTHOR]

Copyright of Journal of the College Of Basic Education is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Display omitted] • G-FA and F-FA were vitrified together based on their compositional complementarity. • Clean vitrified slag was obtained at 1300 °C without water-washing and any additives. • Cr, Ni, Cu could be recovered as Fe-Cr-Ni-Cu alloy. • FA was efficiently reutilized as three separated phases. The increasing application of municipal solid waste incineration (MSWI) emphasises the need for MSWI fly ash (FA) safe treatment. Based on the compositional complementarity of FA from grate furnaces (G-FA) and fluidised bed incinerators (F-FA), we proposed a co-reduction process to treat G-FA and F-FA together for producing vitrified slag and ferroalloys. The clean vitrified slag and Fe-Cr-Ni-Cu alloy were obtained with the mass ratios of 1:9 ∼ 6:4 (G-FA:F-FA) at 1300℃, which is about 300℃ lower than the conventional G-FA vitrification. The metals Zn, Cd, and Pb were mostly volatilised into the flue gas for potential recovery from the secondary FA. The thermodynamic SiO 2 -Al 2 O 3 -CaO ternary system demonstrated that an optimal mass ratio of the two complementary FA types contributes to the system shifting to the low-temperature melting zone. The co-reduction process of G-FA and F-FA could be a promising option for FA beneficial reutilization with environmental advantages. [ABSTRACT FROM AUTHOR]

Introduction: Indoor air quality significantly influences human health because humans can do work and rest indoors. Particulate Matter (PM2.5) is ranked 5th as the leading risk factor for death in the world and causes more than 103 million disabilities. PM2.5 concentrations are the highest, so a monitoring system is needed that can monitor air conditions in real-time and continuously. Methods: Research was conducted using the Research and Development (R&D) type. The scope of the research method is making prototypes andfieldtesting tools. Determination of field test locations is based on indicators such as (i) inadequate ventilation in the respondent's house so that air circulation does not run well; (ii) The family room and bedroom are close to the kitchen and waste incinerator, which has the potential to produce PM2.5 pollutants. Data analysis used descriptive analysis to get a picture of indoor air quality. Results and Discussion: The designed monitoring system was calibrated with the Air Quality Monitor 8 in 1 PM2.5 tool. The average PM2.5 concentration measurement for 24 hours showed that all test points exceeded the standard limit. Room 3 (family room) had the highest PM2.5 concentration, while room 4 (bedroom) had the lowest PM2.5 concentration. Conclusion: The area of air ventilation, mining activities, mining product transportation activities, the intensity of watering roadsides and home yards, and cooking activities influence PM2.5 concentrations. [ABSTRACT FROM AUTHOR]

Incineration is and will remain a proven technology for the safe and sustainable destruction of environmentally hazardous substances. The behavior of non‐CHO elements during combustion plays an important role in the design of incinerators for hazardous waste since they drive the selection and design of the process sequence and of the single equipment. This contribution presents an overview on impacts of the presence of non‐CHO compounds in waste incinerators and provides correlations to estimate the product distribution of sulfur‐ and halogen‐containing compounds as well as for the important fuel properties oxygen demand and heat of combustion of material containing non‐CHO elements. [ABSTRACT FROM AUTHOR]

Despite incineration is an important emission source of toxic pollutants, such as heavy metals and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), it is still one of the most widely used methods for the management of municipal solid waste. The current paper summarizes the results of a 20-year follow-up study of the emissions of PCDD/Fs by a municipal solid waste incinerator (MSWI) in Sant Adrià de Besòs (Catalonia, Spain). Samples of ambient air, soils and herbage were periodically collected near the facility and the content of PCDD/Fs was analyzed. In the last (2017) survey, mean levels in soil were 3.60 ng WHO-TEQ/kg (range: 0.40–10.6), being considerably higher than the mean concentrations of PCDD/Fs in soil samples collected near other MSWIs in Catalonia. Moreover, air PCDD/F concentrations were even higher than those found in a previous (2014) survey, as they increased from 0.026 to 0.044 pg WHO-TEQ/m3. Ultimately, the PCDD/F exposure would be associated to a cancer risk (2.5 × 10−6) for the population living in the surrounding area. Globally, this information indicates that the MSWI of Sant Adrià de Besòs could have had a negative impact on the environment and potentially on public health, being an example of a possible inappropriate management for years. The application of Best Available Techniques to minimize the emission of PCDD/Fs and other chemicals is critical. [ABSTRACT FROM AUTHOR]

Incineration is a common method in municipal solid waste management, which has several advantages such as reducing the volume of waste, but with concerns about exhaust gas and ash management. In this study, heavy metals in bottom ash, secondary furnace ash and fly ash of two waste incinerators in Tehran and Nowshahr were analyzed and its control in cement production was investigated. For this purpose, twelve monthly samples of three types of incinerator ash were analyzed. By combining the studied ashes in the raw materials, the quantity of metals in the cement was analyzed. Finally, by investigating four scenarios based on quantitative variations in the routes of municipal solid waste, ash quantity and the related risk caused by its heavy metals were studied. The results showed that the concentration of heavy metals in the three ash samples of the studied incinerators was 19,513–23,972 µg/g and the composition of the metals included Hg (less than 0.01%), Pb (2.93%), Cd (0.59%), Cu (21.51%), Zn (58.7%), As (less than 0.01%), Cr (15.88%), and Ni (0.91%). The best quality of produced cement included 20% ash and 10% zeolite, which was the basis of the next calculations. It was estimated that the reduction of the release of metals into the environment includes 37 gr/day in best scenario equal to 10.6 tons/year. Ash solidification can be considered as a complementary solution in waste incinerator management. [ABSTRACT FROM AUTHOR]

[Display omitted] • PFAS concentrations in aqueous samples were measured at two landfills. • PFAS in municipal solid waste leachate was more variable than MSW ash leachate. • PFAS concentrations were stable within landfills (coefficient of variation < 50 %) • Leachate in uncovered trenches had the highest fluctuations. • PFAS fluctuations associated with alkalinity, total organic carbon, and ammonia. Studies of per- and polyfluoroalkyl substances (PFAS) fluctuations at landfills have focused on municipal solid waste (MSW) leachate. Few studies exist that evaluate fluctuations (defined by the coefficient of variation, CV) in MSW incinerator ash (MSWA) landfill leachate and that evaluate PFAS fluctuations in stormwater, groundwater, and treated liquids on-site. In this study, aqueous landfill samples (leachate, treated leachate, stormwater, gas condensate, ambient groundwater, and effluent from a groundwater remediation system) were collected from a MSW and an MSWA landfill geographically located within close proximity (less than 40 km). The objective of this study was to compare the leachate compositions between these two landfill types and to evaluate temporal variations. Results indicated that the CV of total detected PFAS concentrations in leachate was higher for the MSW landfill (CV = 43 %) compared to the MSWA landfill (CV = 16 %). The total detected PFAS concentration in MSW leachate samples (mean: 9641 ng/L) was higher than in MSWA leachate samples (mean: 2621 ng/L) (p < 0.05). Within a landfill, PFAS concentrations were correlated (r s > 0.6, p < 0.05) with alkalinity, total organic carbon (TOC), and ammonia. Results from the on-site leachate treatment system at the MSW landfill indicated reductions in COD, TOC, and ammonia; however, the ∑ 26 PFAS concentration increased 3 % after the treatment. Overall, results demonstrated that differences between landfill types and fluctuations in PFAS within landfills should be considered when designing landfill leachate collection and treatment systems to remove PFAS. The comparative analysis in this study can provide insights into optimizing leachate management for MSW and MSWA landfills. [ABSTRACT FROM AUTHOR]

Simulation and modeling of thermal recuperative incinerators may play an important role in enhancing efficiency and ensuring compliance with environmental regulations. In this context, the primary objective of this study is to simulate and comprehensively understand the operation of a geometrically complex thermal recuperative incinerator with an integrated preheater featuring varying levels of heat recovery. To achieve this objective, a simple yet effective 0D model was developed. This modeling approach allows for a holistic evaluation of the performance of the incinerator, enabling the assessment of key parameters, such as temperatures and heat transfer rates, under varying operating conditions. Successful validation of the model is established by comparing its results with measurements from an industrial thermal recuperative incinerator in operation at a vehicle assembly plant, with maximum relative differences of around 9%. Simulations for different percentages of flue gases bypassing the preheater were conducted, indicating a good compromise between heat transfer and pressure drop and a 22% heat recovery at around 50%. The model presented in this paper provides a robust foundation for comprehensively assessing and optimizing the performance of thermal recuperative incinerators and systems that comprise thermal recuperative incinerators, with implications for waste management and sustainable energy recovery systems. [ABSTRACT FROM AUTHOR]

This study investigates a circulating fluidised bed (CFB) incineration plant to examine the concentrations and fingerprints of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and biphenyls (PCBs) at five locations downstream of the post-combustion zone. Sampling encompassed both flue gas and ash, spanning from the high-temperature superheater to the outlet of the baghouse filter, thus covering a wide range of flue gas temperatures. The analysis reveals a continuous increase in PCDD/F and PCB concentrations in the flue gas from the superheater to the inlet of the air pollution control system (APCS). The maximum concentrations observed were 75.8 ng/Nm3 for PCDDs, 219 ng/Nm3 for PCDFs, and 763 ng/Nm3 for PCBs. These values represent 9.14, 11.5, and 6.37 times their respective concentrations at the outlet of the high-temperature superheater. Concurrently, the levels of PCDD/Fs and dioxin-like PCBs (dl-PCBs) in the ash steadily increased along the cooling path of the flue gas within the plant. Comparing dl-PCBs to the total amount of 209 PCB congeners, it was evident that dl-PCBs exhibited a trend more akin to that of PCDD/Fs. A robust linear correlation was observed between dl-PCBs and PCDD/Fs (R2 = 0.99, p < 0.001), surpassing that between PCBs and PCDD/Fs (R2 = 0.92, p < 0.01), suggesting that dl-PCBs share closer formation pathways with PCDD/Fs. Additionally, elemental composition analysis of fly ash samples aimed to explore potential links between fly ash characteristics and PCDD/F and PCB formation. The Cl/S ratio increased from 1.58 to 5.13 with decreasing flue gas temperature. Principal component analysis (PCA) was employed to visualise the concentrations of PCDD/Fs and PCBs in the flue gas alongside elemental contents in the fly ash. With the exception of PCBs in ash, all other PCDD/Fs and PCBs in fly ash exhibited positive correlations with both carbon (C) and chlorine (Cl). Furthermore, a positive relationship between C/Cl and PCDD/Fs-PCBs in fly ash implies that fly ash serves as the primary reaction surface for dioxin generation during low-temperature heterogeneous catalytic reactions. [ABSTRACT FROM AUTHOR]

Industrieschnee or anthropogenic snowfall is a local winter hazard in many European cities and towns under suitable anticyclonic conditions and in the vicinity of persistent local water vapour sources and air pollution. Here, we overview the formation of Industrieschnee and describe a case study event from Bern, Switzerland, comparing the estimated mass of snow deposited with the water vapour emissions from a local incinerator. We speculate that previous European Industrieschnee events may have been considerably under‐reported, or falsely attributed to surface hoar frost (reif) or the accretion of rime (raureif). [ABSTRACT FROM AUTHOR]

Pyrolysis is a combustion process of woody biomass conducted under low or no oxygen conditions. It converts any kind of biomass into biochar, bio-oil, or biogas. Hence plants' woody material can also be converted into bioenergy products. Valorization of woody biomass in the form of energy-rich compound biochar is a more sustainable technique as compared to conventional burning which leads to toxicity to the environment. Innovations and the need to limit open burning have resulted in numerous mobile and fixed plant pyrolysis methods that burn a variety of woody residues. Production technologies that reduce the need for open burning, the main source of potential pollutants, fall under the regulations in the Clean Air Act of 1990. This Act is the legal instrument to regulate air pollution at its source across the United States of America and it is implemented and enforced through the Environmental Protection Agency, in coordination with sister agencies. One newer innovation for reducing wood residues and emissions is an air curtain incinerator. Currently, the Clean Air Act regulates stationary solid waste incinerators, and this is also applied to mobile air curtain incinerators burning woody biomass. However, other woody biochar production methods (e.g., flame cap kilns) are not subjected to these regulations. Discrepancies in the interpretation of definitions related to incineration and pyrolysis and the myriad of differences related to stationary and mobile air curtain incinerators, type of waste wood from construction activities, forest residues, and other types of clean wood make the permit regulations confusing as permits can vary by jurisdiction. This review summarizes the current policies, regulations, and directives related to in-woods biochar production and the required permits. [ABSTRACT FROM AUTHOR]

The long-term leaching behavior of incineration bottom ash (IBA) was studied with large-scale samples from two German waste incinerators with grate technology. The observation period was up to 281 days. The aging processes proceeded faster in the outdoor storage of the samples. The dominant factor in the leaching behavior is the pH, which starts at values above 12 and decreases to values below 10 (outdoors, <11 indoors). Most heavy metals exhibit minimum solubility in this pH range. The solubility of Sb depends on the prevailing Ca concentration, due to the formation of low-soluble Ca antimonate. The very low sulfate concentrations observed in the leaching tests with fresh IBA could be explained by the presence of ettringite. In the course of the aging reaction, ettringite is transformed into gypsum. The results from batch tests were compared with those from column tests, showing reasonable agreement. Leaching dynamics can be better followed with column tests. All results confirm that the use of IBA is possible under German law. [ABSTRACT FROM AUTHOR]

The formation and emission of sulfur trioxide (SO3) in sulfur recovery unit has received increasing attention due to its adverse effects on the operation of plant and environment. Due to the excess oxygen, high concentration of SO2 and high temperature, SO3 formation in the sulfur recovery unit tail gas incinerator may significantly increase. A small horizontal tube reactor was employed to simulate the homogeneous oxidation of SO2 in the tail gas incinerator. The SO3 concentration was measured with a controlled condensation method at the outlet of the reactor. The present work focuses on the gas-phase chemistry and examines the impact of different combustion parameters and atmospheres on the formation of SO3 in the tail gas incinerator. Experiment results show that the increased O2 and SO2 concentrations along with increasing temperature are favorable for enhancing SO3 formation over the range of tested parameters. The presence of water vapor has an enhancing effect of SO2 oxidation in the experiments conducted. No significant effect of CO2 was found to the oxidation of SO2. [ABSTRACT FROM AUTHOR]

Copyright of Refractories / Naihuo Cailiao is the property of Naihuo Cailia (Refractories) Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Annually about 5.7 million tons of waste incinerator ash accumulate in Germany through the incineration of municipal waste. The new method of electrodynamic fragmentation allows waste incinerator ashes with complex material compositions to be broken at material interfaces and then sorted into materially pure components. The aim of current ASHCON research project is to substitute natural aggregate of the grain fraction 2/8 mm in conventional formulations for ready‐mixed concrete and concrete blocks by these secondary raw materials in order to keep them within the material cycle and reduce the use of primary raw materials. Since the utilization of fragmented waste incinerator ashes in concrete must be below the limit values with regard to possible pollutant concentrations (e.g. heavy metal concentrations), the suitability of a so‐called non‐destructive neutronic analysis method on real samples is also being investigated within the ASHCON project. The first results of sample collection, preparation and analysis as well as material properties of the produced concretes with the implementation of mineral residues from waste incinerator ashes are presented in this paper. [ABSTRACT FROM AUTHOR]

Wet scrubber systems (WSSs) are commonly used for effective flue gas cleaning by removing acid gases and dust. To determine the influence of a WSS on polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) and flue gas particles, a field study was carried out in a full-scale municipal solid waste (MSW) incinerator (850 t/d). Phase-separated samples at four flue gas sampling points and two scrubbing solution sampling points were collected for PCDD/F analysis. Two particle samples at the WSS inlet and outlet were simultaneously obtained for TEM-EDS analysis. The memory effect inside the WSS apparently elevated the PCDD/F I-TEQ concentration from 0.0056 to 0.0088 ng I-TEQ Nm−3 by increasing the mass concentrations of 17 congeners. A PCDD/F flux chart was established to interpret the adsorption/desorption mechanism of PCDD/Fs inside the WSS that showed apparent desorption from scrubbing solution. The potential interaction relationship between PCDD/F and flue gas particles were also observed, that was, the desorbed PCDD/Fs from scrubbing solution might be adsorbed by flue gas particles again and therefore enhanced the concentration of solid-phase PCDD/Fs from 0.0236 to 0.0411 ng Nm−3. Furthermore, TEM-EDS analysis indicated that the WSS could evidently remove some soluble particles and reduce the particle size. And the variation in morphology, elemental composition, and distribution of flue gas particles were observed during the scrubbing process. This study systematically analyzed the memory effect of PCDD/Fs and firstly investigated the specific impact of WSS on flue gas particles, thereby improving the comprehensive understanding of WSS applications. [Display omitted] [ABSTRACT FROM AUTHOR]

The amount of medical waste generated has increased enormously since the COVID-19 outbreak. An incineration process is the main method that is usually used to treat this waste, causing an increase in both medical waste bottom ash (MWBA) and medical waste fly ash (MWFA). In this work, the physical and chemical characteristics of MWFA and MWBA were reviewed. This ash contains high levels of polychlorinated dibenzo-p-dioxin (PCDD), dibenzofurans (PCDFs), and heavy metals. Furthermore, medical waste ash appears to have high leachability in the toxicity characteristics leaching procedure (TCLP) test and the European standard test (EN 12457). Owing to its toxicity, medical ash can be treated using various methods prior to disposal based on the covered review. These techniques include chemical, supercritical fluid, cement-based, melting, microwave, and mechanochemical techniques. The shortcomings of some of these treatment methods have been identified, such as the emission of high levels of chlorine from the melting technique, limited applications of the flotation method on the industrial scale, long-term stability of leachate treated by cement-based methods that have not been confirmed yet, and high energy consumption in the supercritical technique. This review also covers possible applications of medical waste ash in cement production, agriculture, and road construction. [ABSTRACT FROM AUTHOR]

[Display omitted] • The first study for dioxin prediction with extensive online dioxin datasets. • The application of SVM, RF, LSTM, and CNN models for dioxin emission prediction. • MSE improves by 36.5% in the LSTM model through time series input. • The cumulative effect of dioxin formation is fetched by deep-learning models. The immeasurability of real-time dioxin emissions is the principal limitation to controlling and reducing dioxin emissions in municipal solid waste incineration (MSWI). Existing methods for dioxin emissions prediction are based on machine learning with inadequate dioxin datasets. In this study, the deep learning models are trained through larger online dioxin emissions data from a waste incinerator to predict real-time dioxin emissions. First, data are collected and the operating data are preprocessed. Then, the dioxin emission prediction performance of the machine learning and deep learning models, including long short-term memory (LSTM) and convolutional neural networks (CNN), with normal input and time-series input are compared. We evaluate the applicability of each model and find that the performance of the deep learning models (LSTM and CNN) has improved by 36.5% and 30.4%, respectively, in terms of the mean square error (MSE) with the time-series input. Moreover, through feature analysis, we find that temperature, airflow, and time dimension are considerable for dioxin prediction. The results are meaningful for optimizing the control of dioxins from MSWI. [ABSTRACT FROM AUTHOR]

Traditional incinerators achieve the thermal requirements through heat transfer and heat radiation. However, the early recovery of flue gas preheats the air and yields nitrogen oxide (NOx) to rise in the combustion of overoxygen. The operation of an incinerator inevitably implies the release of greenhouse gases and emissions of NOx harmful to the human health. The administrator of one laboratory incinerator in Taiwan sought to optimize the operation conditions such as temperature or oxygen level of the combustion products within the combustion chamber to minimize the release of pollutants and maximize the efficiency of combustion. In this phase, air-fuel ratio control and air volume control are regarded as the first priority. A numerical model of the laboratory-scale plant in southern Taiwan is established by using enhanced wall treatment and coupling the thermochemical conversion of volatile waste to the gaseous combustion of the released syngas. The model allows users to characterize the temperature and retention time of the combustion products for the verification of the fulfillment of the existing regulation for NOx and oxygen level in incineration plants. It shows trade-off relationship between combustion efficiency of fuel and emissions (NOx and CO) in surveying cases of air-fuel ratio (AFR) ranges from 1.5∶1 to 14.4∶1 according to numerical results. Increasing the air volume enhances this trend. In this study, it shows the lowest emissions of NOx in case of AFR=1.5∶1 , but worse combustion efficiency. Meanwhile, to increase the air volume by 1.15 times suppress most CO and about 28% NOx, but increases by 6% the residual fuel. The averaged distribution of retention time of particles in this study ranged from 30 to 50 s, and is provided for further improvement of geometry in the next phase. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Engineering (17264073) is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The service life of a phenol acetone salt-containing waste vertical incinerator (PASWVI) is largely dependent on the internal working conditions and the furnace lining refractories. In this work, the internal working conditions of PASWVI during the steady operation have been comprehensively investigated with aid of Ansys Fluent. Considering the effects of the waste fluid injection rate on both the high temperature zone of the furnace wall and the erosion of the furnace bottom, the waste fluid injection rate of 8 m/s is regarded as the suitable industrial operation condition. Based on this, the erosion rates of corundum-mullite brick and corundum-composite spinel brick for 1 h are calculated to be 3.60 × 10−3 kg/m2 and 1.68 × 10−3 kg/m2, respectively. This work will provide valuable references for the optimization of refractories used in PASWVI. [ABSTRACT FROM AUTHOR]

The external heat exchanger (EHE) can solve the problem of the insufficient heating surface due to the large‐scale circulating fluidized bed (CFB) boiler effectively; furnace temperature and bed temperature can be regulated quickly and accurately with the adjustment of the solids circulation rate (SCR). The ash differs from coal‐fired boilers in particle size, density, and other physical parameters, so the circulation and heat transfer characteristics are not identical. The results of SCR and pressure distribution in a cold CFB experimental system with an EHE in which the height of the partition (HP) could be adjusted were analyzed. Experiments studied the effect of fluidized air velocity in the riser (Ug), HP of the EHE, and the pressure of the supply air chamber (PSA) in the EHE on SCR using quartz sand with an average size of 0.239 mm. It was noted that SCR increased with Ug and PSA in the range of 7.01–28.37 g/s with the increase in Ug, and the maximum value of SCR was obtained when PSA was 750 Pa and the HP was 80 mm. The experiments also noted that the increase in SCR significantly affected the pressure distribution in the region of high solids content (EHE and the region above 600 mm in the riser). A reference to the above characteristics of SCR and pressure distribution variations can be considered for operating commercial CFB waste incinerators. [ABSTRACT FROM AUTHOR]

Polyhalogenated carbazoles (PHCZs) are recently raising much attention due to their toxicity and ubiquitous environmental distribution. However, little knowledge is known about their ambient occurrences and the potential source. In this study, we developed an analytical method based on GC-MS/MS to simultaneously determine 11 PHCZs in PM 2.5 from urban Beijing, China. The optimized method provided low method limit of quantifications (MLOQs, 1.45–7.39 fg/m3) and satisfied recoveries (73.4%–109.5%). This method was applied to analyze the PHCZs in the outdoor PM 2.5 (n = 46) and fly ash (n = 6) collected from 3 kinds of surrounding incinerator plants (steel plant, medical waste incinerator and domestic waste incinerator). The levels of ∑ 11 PHCZs in PM 2.5 ranged from 0.117 to 5.54 pg/m3 (median 1.18 pg/m3). 3-chloro-9H-carbazole (3-CCZ), 3-bromo-9H-carbazole (3-BCZ), and 3,6-dichloro-9H-carbazole (36-CCZ) were the dominant compounds, accounting for 93%. 3-CCZ and 3-BCZ were significantly higher in winter due to the high PM 2.5 concentration, while 36-CCZ was higher in spring, which may be related to the resuspending of surface soil. Furthermore, the levels of ∑ 11 PHCZs in fly ash ranged from 338 to 6101 pg/g. 3-CCZ, 3-BCZ and 36-CCZ accounted for 86.0%. The congener profiles of PHCZs between fly ash and PM 2.5 were highly similar, indicating that combustion process could be an important source of ambient PHCZs. To the best of our knowledge, this is the first research providing the occurrences of PHCZs in outdoor PM 2.5. [ABSTRACT FROM AUTHOR]

This article introduces Fairkauf, a charitable thrift store, in Stuttgart, Germany and analyzes its work and participation in alternative economies of reuse, repair, repurposing, sharing, and care, and the store's contributions to ecological and social sustainability. Thrift stores are contemporary responses to overproduction, hyper-consumption, social inequality, and ecological degradation. This article provides a nuanced ethnographic description of a thrift store. Such stores are often overlooked, yet they play a crucial role in individual and urban sustainability efforts. They are spaces of incidental sustainability that do not loudly advertise their work, but quietly help thrifters pursue more ecological lifestyles and help cities divert huge quantities of materials from landfills and incinerators. Thrift stores' labor connects thrifters to activities and networks of often similarly hidden sustainability efforts by ordinary people across the world. Theoretically, I engage the role of thrift stores in alternative economies that contribute to more ecologically and socially sustainable lifeworlds and futures. [ABSTRACT FROM AUTHOR]