Incineration Process Research Articles

Insight into the formation of polychlorinated dibenzo-p-dioxins and dibenzofurans in hazardous waste incineration and incinerators: Formation process and reduction strategy

Incineration technology has been widely adopted to safely dispose of hazardous waste (HW). While the incineration process causes the formation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). Due to its extreme toxicity, many scholars have been committed to determining the PCDD/F formation process and reducing emissions in incinerators. Previous studies ignored the impact of incineration and fluctuation of feeding materials on PCDD/F formation in hazardous waste incinerators (HWIs). In this study, differences in PCDD/F formation between HWIs and municipal solid waste incinerators (MSWIs) were pointed out. The incineration section in HWIs should be carefully considered. Laboratory experiments, conventional analysis and thermogravimetry experiments were conducted. An obvious disparity of PCDD/F formation between 12 kinds of HWs was found. Distillation residue was found with remarkably higher PCDD/F concentrations (11.57 ng/g). Except for the Cl content, aromatic rings and C–O bond organics were also found with high correlation coefficients with PCDD/F concentrations (>0.92). And PCDD/Fs were formed through a chlorination process and structure formation process. All of these are helpful to further understand the PCDD/F formation process during HW incineration, optimize the operation conditions in HWIs and reduce the emission pressure of PCDD/Fs in the future.

First-principles study on the heterogeneous formation of environmentally persistent free radicals (EPFRs) over α-Fe2O3(0001) surface: Effect of oxygen vacancy

Metal oxides with oxygen vacancies have a significant impact on catalytic activity for the transformation of organic pollutants in waste-to-energy (WtE) incineration processes. This study aims to investigate the influence of hematite surface oxygen point defects on the formation of environmentally persistent free radicals (EPFRs) from phenolic compounds based on the first-principles calculations. Two oxygen-deficient conditions were considered: oxygen vacancies at the top surface and on the subsurface. Our simulations indicate that the adsorption strength of phenol on the α-Fe2O3(0001) surface is enhanced by the presence of oxygen vacancies. However, the presence of oxygen vacancies has a negative impact on the dissociation of the phenol molecule, particularly for the surface with a defective point at the top layer. Thermo-kinetic parameters were established over a temperature range of 300–1000 K, and lower reaction rate constants were observed for the scission of phenolic O-H bonds over the oxygen-deficient surfaces compared to the pristine surface. The negative effects caused by the oxygen-deficient conditions could be attributed to the local reduction of FeIII to FeII, which lower the oxidizing ability of surface reaction sites. The findings of this study provide us a promising approach to regulate the formation of EPFRs.

Research on the Flow Parameters of Waste Motion in a Rotary Kiln with the Use of the Tracer Method.

The motion of input material in a rotary kiln is an important aspect of its operation. This can be observed especially in the case of the implementation of the hazardous waste incineration process in this device. The values of the flow parameters, mainly the residence time and the degree of mixing, can determine the proper and safe treatment of waste. The relationships that occur in the layer of solid material in a rotary kiln have not been completely recognized. This article presents a research method that involves an experiment on a laboratory stand simulating a rotary kiln in association with a dedicated algorithm. Multi-criteria tests were carried out. The adopted research method was the tracer method. It used a tracer which, subject to the same transport conditions as other material particles, provided information on the characteristic of the motion of tested materials in the rotating cylinder. The application based on the residence time distribution (RTD) algorithm returned information about the characteristics of the motion of the material in the rotary cylinder in terms of residence time distribution and the degree of mixing. This tracer method, together with stimulus impulses on the grate and a dedicated RTD algorithm, was used here as a sensor method to examine the characteristics of material motion on various grate systems. The data obtained as a result of this research may include, among others, the boundary conditions for numerical simulations of processes carried out in a rotary kiln.

Potential Integration of Waste to Energy (WtE) and Carbon Mineralization Technology in Indonesia

Several issues such as environment, finance, and policies in the development of Waste to Energy (WtE) in Indonesia require strategic and appropriate handling. This study offers a promising solution by integrating WtE incineration process with carbon mineralization as one of Carbon Capture, Utilization, and Storage (CCUS): adding CO2 capture technology to the existing system and CO2 will be reacted with fly ash residue producing insoluble carbonates to stabilize the heavy metals contained. Moreover, with a combustion capacity of 1000 tons of waste/day scenario, it is equivalent to a reduction of carbon emissions of up to 25 tCO2 per day. A feasibility study in Estonia revealed that if WtE is integrated with carbon mineralization, the resulting Net Present Value (NPV) is up to 9,209,662 EUR. This can be an opportunity for Indonesia to solve the financial issues as the existing WtE only generates 133,500 EUR of NPV. Additionally, the existing policy states that the construction of a WtE plant must be accompanied by a residue treatment plant facility. So that in addition to increasing profits and environmental benefits, this integration also can help simplify the complexity of WtE development requirements because residue treatment becomes easier.

Time-series prediction using a regularized self-organizing long short-term memory neural network

Industrial process data are naturally in the form of complex time-series with high nonlinearities and dynamics. Long short-term memory (LSTM) networks are suitable for developing prediction models to handle nonlinear and dynamic process. However, LSTM neural networks have typically large and predefined structures, which may result in overfitting, and an optimal hidden neurons for a given problem cannot be automatically obtained. For this reason, a regularized self-organizing LSTM (RSO-LSTM) is proposed to optimize both the structure and the parameters of the network. First, an adaptive learning algorithm based on l2-norm regularization is introduced for parameter adjustment. Thereafter, both the prediction accuracy and weight dispersion are considered to avoid overfitting. Second, a growing strategy is designed based on hidden neuronal sensitivity. The structure of the LSTM can then be determined automatically with improved compactness. Finally, a convergence analysis is performed to ensure the feasibility of RSO-LSTM. To demonstrate the merits of the proposed RSO-LSTM for time-series​ prediction, its results for three benchmark experiments and real industrial data of a municipal solid waste incineration process were examined and compared with those of other methods. The results indicated the superiority and potential of RSO-LSTM for industrial applications.

Occurrence and formation of environmentally persistent free radicals in incineration and their impact on soil and water

Incineration is a thermal waste treatment technique that can be understood as a controlled combustion process with the primary objective of volume reduction of waste mass. Combustible waste including gaseous, aqueous, muddy, molten, and solid waste is typically deal with incineration at temperature ranges from 750 to 1200 °C. End products of incineration include a considerable amount of particulate matter (PM) and pollutants. Particulate matter released from the incineration process plays an important role in forming environmentally persistent free radicals (EPFRs) which are the most toxic and stable substance emitted from the incinerator. Other major compounds released during the incineration process are dioxins, polychlorinated biphenyls, polychlorinated naphthalene, chlorinated benzenes, and polycyclic aromatic hydrocarbons (PAH). Although incineration is significantly used to control the waste crisis but emissions of toxic substances from an incinerator have various health impacts on the environment and humans. Long exposures to these hazardous compounds lead to respiratory and cardiovascular diseases. These toxic compounds participate in various redox activities as well as metal complexation events and deteriorate the physiochemical parameter of soil and water. The aim of the present study is to summarize the existing knowledge regarding the formation of harmful compounds released during waste incineration and major environmental challenges associated with them.

Distributions of trace elements within MSWI bottom and combined ash components: Implications for reuse practices

Concentrations of 25 inorganic elements were measured in both bulk ash and individual ash components from residuals at three municipal solid waste incineration (MSWI) facilities in the US (two combined ash (CA) and one bottom ash (BA)). Concentrations were assessed based on particle size and component to understand the contribution from each fraction. The results found that among facilities, the finer size fractions contained elevated concentrations of trace elements of concern (As, Pb, Sb) when compared to the coarse fraction, but concentrations varied among facilities depending on the type of ash and differences in advanced metals recovery processes. This study focused on several constituents of potential concern, As, Ba, Cu, Pb, and Sb, and found that the main components of MSWI ash (glass, ceramic, concrete, and slag) are sources of these elements in the ash streams. For many elements, concentrations were significantly higher in CA bulk and component fractions opposed to BA streams. An acid treatment procedure and scanning electron microscopy/energy-dispersive x-ray spectroscopy analysis revealed that some elements, such as As in concrete, are result of the inherent properties of the component, but other elements, such as Sb, form on the surface during or after incineration and can be removed. Some Pb and Cu concentrations were attributed to inclusions in the glass or slag introduced into the material during the incineration process. Understanding the contributions of each ash component provides critical information for developing strategies to reduce trace element concentrations in ash streams to promote reuse opportunities.

Numerical simulation modelling on whole municipal solid waste incineration process by coupling multiple software for the analysis of grate speed and air volume ratio

Uncertainties in the calorific value and composition of municipal solid waste (MSW), the variability in operations, equipment performance decline, maintenance needs, and other dynamic factors make it challenging for operational experts to accurately gauge the overall combustion impact under fluctuating conditions. There is a need for a visual numerical simulation of the full MSW incineration (MSWI) process, with a focus on the effectiveness of the grate speed and air volume ratio. Unfortunately, software like Aspen Plus struggles to visually depict the effect of typically manipulated variables such as grate speed, and it is not well-suited for simulating solid-phase combustion and flue gas treatment. In response to these challenges, our study introduces a numerical simulation method for the MSWI process using a multi-software coupling approach. This simulation method incorporates (a) the use of custom software for simulating solid-phase combustion on the grate, (b) the application of Computational Fluid Dynamics (CFD) software for gas-phase combustion in the furnace, and (c) the utilization of chemical process simulation software for non-grate solid-phase combustion. The benchmark condition was determined using real-time running data from the Beijing MSWI Power Plant. The results show that for the incinerator’s third flue, flue gas G1, and flue gas G3, the relative errors between the simulated and actual values for flue gas temperature and oxygen concentration were 0.3% and 1.1%, 3.5% and 20%, and 0.2% and 20% respectively. In addition, we used eight non-benchmark conditions to study the effects of grate speed and air volume ratio. When the grate speed was gradually increased from 6 m/h to 8 m/h, O2, CO2, sulfur dioxide (SO2), sulfur trioxide(SO3), nitrogen monoxide (NO), and nitrogen oxide (NO2) at G1 had error fluctuation ranges of 5.9%− 48.5%, 2.5%− 11.5%, 10.42–28.57%, 7–23%, 29.10–45.52%, and 24.39–48.78%, respectively. When the primary air ratio was gradually increased from 0.84 to 0.96, the O2 concentration at G1 exhibited a steady upward trend. The simulation results provide insights into the adjustment range of the manipulated variables and offer additional support for the visualized and optimized control operation of the MSWI plant.

Experimental investigation on sun-dried bricks with addition of lignin

Brick is one of the oldest building material used for masonry works in construction. A major problem that exist in construction field is extinction of traditional as well as conventional building materials like bricks, cement, etc. And also achieving inadequate strength in building due to reduced usage of natural raw materials. The abundant availability of bio-wastes and their impacts on the environment is the major problem faced in recent times. Coconut husk is an agricultural & coir industrial waste present in abundant quantity, which is being dumped on the roadside and disposed by incineration process. This leads to environmental pollution due to emission of CO2 during incineration of coconut husk. This project attempts to provide an alternative for the above issues. It carry out an experimental study to extract suitable product from organic waste and effective addition of this product to existing building materials. This will help in improving the strength, durability and quality of the material. And also the experiments are carried out to study the properties of the material. The expected inference from this project is improvement of compressive strength of the unburnt bricks with the addition of the tissue (lignin) that has been extracted from the coir pith. The project deals with extraction process of lignin from coconut husk in an inexpensive way and addition of the lignin to bricks and comparison of properties to that of conventional bricks and obtained unburnt clay bricks.

Modification of Concrete Composition Doped by Sewage Sludge Fly Ash and Its Effect on Compressive Strength.

The sustainable development of construction materials is an essential aspect of current worldwide trends. Reusing post-production waste in the building industry has numerous positive effects on the environment. Since concrete is one of the materials that people manufacture and use the most, it will continue to be an integral element of the surrounding reality. In this study, the relationship between the individual components and parameters of concrete and its compressive strength properties was assessed. In the experimental works, concrete mixes with different contents of sand, gravel, Portland cement CEM II/B-S 42.5 N, water, superplasticizer, air-entraining admixture, and fly ash from the thermal conversion of municipal sewage sludge (SSFA) were designed. According to legal requirements in the European Union, SSFA waste from the sewage sludge incineration process in a fluidized bed furnace should not be stored in landfills but processed in various ways. Unfortunately, its generated amounts are too large, so new management technologies should be sought. During the experimental work, the compressive strength of concrete samples of various classes, namely, C8/10, C12/15, C16/20, C20/25, C25/30, C30/37, and C35/45, were measured. The higher-class concrete samples that were used, the greater the compressive strength obtained, ranging from 13.7 to 55.2 MPa. A correlation analysis was carried out between the mechanical strength of waste-modified concretes and the composition of concrete mixes (the amount of sand and gravel, cement, and FA), as well as the water-to-cement ratio and the sand point. No negative effect of the addition of SSFA on the strength of concrete samples was demonstrated, which translates into economic and environmental benefits.

The physical encapsulation and chemical fixation of Zn during thermal treatment process of municipal solid waste incineration (MSWI) fly ash

Thermal treatment is a promising treatment technology of municipal solid waste incineration (MSWI) fly ash because of its detoxication and volume reduction. However, the relationship between immobilization of heavy metals and mineral transformation during thermal treatment remains unclear. In this study, the immobilization mechanism of Zn during thermal treatment process of MSWI fly ash was investigated by experiment and calculation. The results show that addition of SiO2 facilitates transition of dominant minerals from melilite to anorthite during sintering, increases liquid content during melting and improves liquid polymerization degree during vitrification. ZnCl2 tends to be physically encapsulated by liquid phase, and ZnO is mainly chemically fixed into minerals at high temperature. Increase in both liquid content and liquid polymerization degree favors the physical encapsulation of ZnCl2. The decreasing order of chemical fixation ability of minerals to ZnO is spinel > melilite > liquid > anorthite. To better immobilize Zn during sintering and vitrification process chemical composition of MSWI fly ash should be located in melilite and anorthite primary phases of pseudo-ternary phase diagram, respectively. The results are helpful to understand immobilization mechanism of heavy metals and avoid volatilization of heavy metals during thermal treatment process of MSWI fly ash.

THE IMPORTANCE OF HEALTH LEGAL REGULATIONS ON HOSPITAL B3 WASTE MANAGEMENT

The hospital as one of the health service facilities as stated in the Regulation of the Minister of Environment and Forestry of the Republic of Indonesia No. 56 of 2015, it is mandatory to carry out B3 waste management which includes reducing and segregating B3 waste, storing B3 waste, transporting B3 waste, processing B3 waste, burying B3 waste, and/or storing B3 waste. Hazardous waste generated from laboratory activities is in the form of residual healing processes for sick people such as additives for washing wounds, blood washing, cancer therapy processes, surgical practices, pharmaceutical products, and residue from incineration processes. The waste generated can pollute the environment. The method used is a systematic review through journal reviews regarding the implementation of legal regulations on the implementation of waste management in hospitals. This systematic review shows that laws and ministerial regulations governing the issue of waste management in hospitals already exist and are clearly described. However, in practice, not all hospitals are aware of managing B3 waste properly. This means that the hospital has not optimally implemented environmental management in accordance with applicable laws and regulations. Lack of concern or commitment from the leadership of hospitals and health care facilities, lack of understanding of health care facility staff, and legal cases in health care facilities. The implementation of laws and regulations related to the management of B3 waste in healthcare facilities, especially hospitals, has generally been carried out based on the applicable legal regulations. However, there are still a number of cases of negligence or lack of awareness on the part of the hospital, both from the low awareness of actors or health workers in providing services so as to make a negative contribution to the environment and society.

Analysis and research on the thermal system of waste incineration power generation unit based on heat balance method

The thermal system of waste incineration power generation unit is simple and small in capacity, but the original parameters are few. It needs to calculate the thermal system and derive the parameters by using the conventional heat balance method to obtain the complete thermal system parameters. In this paper, an accurate and perfect thermodynamic model of waste incineration power generation is established to solve the problems of low thermal efficiency and high unit investment cost of the waste incineration power generation. To investigate the internal relationship between the incinerator unit structure, operating parameters, waste calorific value and waste combustion process, optimize the combustion status of different incinerators burning different waste, and realize its stable and efficient operation, it is necessary to study the impact of changing operating parameters and different incinerator structures on the waste incineration process, as well as the incineration law of a single incinerator unit structure burning waste with different calorific value. Based on the two-fluid model of primary oxygen supply and secondary oxygen supply, a newly developed thermodynamic model for waste incineration engineering was developed, and the direct coupling between the reciprocating grate and the incinerator was realized in the software. Using the conventional heat balance method and constant flow calculation, the flow parameters of the thermal system under the design condition are calculated through the design pressure parameters to calculate the power generation and thermal economy index of the condition; and the relevant steam extraction flow is checked and verified. The experimental results show that the net thermal efficiency of waste incineration increases from 19. 73% to 26. 40%, and the energy utilization efficiency also increases by 0. 18%. The net thermal efficiency of the optimized integrated power generation system is always higher than that of the independent power generation system more than 0.16%. The model method used in this paper can reduce the influence of incinerator arch structure on bed combustion to a greater extent, which makes the simulation results close to reality, greatly reduces the calculation cost, and is conducive to the industrial application of simulation in the field of waste incineration.

Evaluation of the heating (Calorific) value of municipal wet solid waste from Kabagarame Dumping site in Bushenyi District, Uganda.

Modern management of waste around the world has moved from waste disposal to energy recovery through WtE. Technologies that can be utilized to recover energy from MSW via thermal conversion processes such as incineration, gasification, pyrolysis, biochemical conversion processes and chemical conversion. The aim of this research was to evaluate the heating (calorific) value of municipal wet solid waste from Kabagarame dumping site in Bushenyi District, Uganda. Wet solid waste samples were analyzed, the heating value of the wastes were evaluated. The results showed that other organics had the highest calorific value of 26.22 MJ/kg, followed by paper 16.60 MJ/kg, followed by food waste 16.51MJ/kg and then wood 16.14 MJ/kg on dry matter basis. The results on the heating value on wet basis showed that other organics had the highest calorific value of 12.82 MJ/kg, followed by paper 14.04 MJ/kg, followed by food waste 13.66 MJ/kg and then wood 9.89 MJ/kg. The heating value of plastics was not obtained since they are recovered from the dumping site and recycled. This energy can be harnessed by different production facilities particularly Tea factories in the region through incineration process so as to generate heat necessary for their production processes. In conclusion, results from this research also suggest that understanding the composition of municipal solid waste is essential for creating the best disposal strategy, so that recovering resources trapped in the wastes can be optimized. It is therefore necessary that energy derived from municipal solid wastes can be taken into account in the national energy budget. Keywords: Heating value, solid waste, Kabagarame and dumping site.

Critical Review on Utilization of Incinerated Biomedical Waste Ash to Improve Physico-Mechanical Properties of Concrete Blocks

Waste generation has increased considerably worldwide in the last few decades. Solid wastes encompass the heterogeneous mass of throwaways from the urban community as well as the homogeneous accumulations of agricultural, industrial and mineral wastes. Waste generated from biomedical activities represents a real problem of living nature and human world. A proper waste management system should be required to dispose hazardous biomedical waste and incineration should be the best available technology to reduce the volume of this hazardous waste. The incineration process destroys pathogens and reduces the waste volume and weight but leaves a solid material called biomedical waste incineration ash as residue which increases the levels of heavy metals, inorganic salts and organic compounds in the environment. Disposal of biomedical waste ash in landfill without proper treatment may cause contamination of groundwater due to leachate as metals are not destroyed during incineration. The limited space and the high cost for land disposal led to the development of recycling technologies and the reuse of ash in different systems. There is a scope of utilization of incinerated biomedical waste ash (IBWA) in the production of concrete.This review of literature research paper is intended to evaluate the feasibility of using biomedical waste ash as partial replacement of cement in concrete

STUDIES ON GAS EMISSIONS RESULTING FROM MUNICIPAL WASTE INCINERATION

The purpose of this paper is the study of MSW incineration and the analysis of the results of gas emissions obtained from the process. The waste incineration process was monitored for 30 minutes, during which continuous measurements were made of the process parameters and the resulting emissions.

Research on migration and transformation behavior of selenium during the dual-alkali wet flue gas deacidification process in the simulated flue gas

Selenium easily escapes from the existing air pollution control devices (APCDs) used in municipal waste solid incineration (MSWI), which poses a threat to both the ecosystem and human health. Dual-alkali wet flue gas deacidification (DAWFGD) has been recently applied in MSWI power plants to improve the purification of flue gas. This technology provides a new route for the coordinated control of selenium in the DAWFGD device, which removes acidic gas simultaneously. In this study, a laboratory-scale DAWFGD system was constructed to investigate the migration and transformation behavior of selenium during the absorption and regeneration process in the DAWFGD system. The results showed that the Na2CO3 solution could effectively absorb SeO2, and the absorption efficiency could reach up to 97.09% by increasing the Na2CO3 concentration. High-concentration CO2 has less of an absorption inhibition effect on gaseous selenium compared to low-concentration HCl and SO2. The absorption of SeO2 was adversely affected by the decrease in pH value of the absorption solution caused by an increase in SO2 concentration. However, the addition of a small amount of alkali solution (OH–) into the absorption solution could well recover its absorption performance for SeO2. During the regeneration process, the precipitation ratio of selenium from the aqueous phase to the solid phase increased with the molar ratio of Ca/S increasing. Besides, selenium was found to be in the form of selenite during both the absorption and regeneration processes. This study helps to evaluate the potential of DAWFGD in MSWI power plants for removing SeO2 from flue gas and provides a theoretical reference for the treatment of gas-phase selenium in the waste incineration process.

The controlled incineration process as an alternative to handle MSW and generate electric energy in the state of Guanajuato, Mexico

Municipal solid waste (MSW) is a severe problem for cities on a global scale. Its correct management and final disposal are imperative to avoid negative impacts on society. Mexico and its constitutional states present conservative management and final disposal of MSW (low recycling and high use of open dumps). This study analyzes the technical, environmental, and economic feasibility of using a controlled incineration process in Guanajuato (Mexico) to generate electric energy and reduce the need to use landfills or open dumps for final disposal. The results indicate technical feasibility with Waste-to-Energy plants (WtE) capable of handling between 2000 and 3000 T/day, reducing CO2eq emissions by larger than 50% compared with landfills. Under the assumed parameter, economic feasibility is the main drawback since the NPV, IRR, and LCOE indicate no profitability; however, an increment in plant efficiency, a reduction in O&M cost, and a discount rate decrement led to achieving feasibility. The study introduces the Overall Decision-making Factor (ODMF) as a parameter of quantitative comparison among the proposed plants. This parameter considers each plant's main technical, environmental, and economic factors.

Dynamic modeling of multi-input and multi-output controlled object for municipal solid waste incineration process

Municipal solid waste incineration (MSWI) is an important part of energy recovery and sustainable development, constructing the model of controlled object is the basis of studying its optimal control. MSWI is a typical multi-input and multi-output industrial process, which has many uncertain characteristics such as strong nonlinearity and multivariable coupling. To solve this problem, a model of controlled object in MSWI process is proposed in this paper. Firstly, the MSWI process based on grate incinerator is analyzed to summarize its relevant variables and control requirements. Secondly, the solid phase and gas phase of MSWI process are divided to construct material balance equations of subsystems. Next, the energy transfer process in incinerator is deduced and calculated through thermodynamic laws. Finally, the validity of the model is verified by the process data of a MSWI plant in Beijing, China, which lays a model foundation for the study of the optimal control of MSWI process.

Event-triggered-based self-organizing fuzzy neural network control for the municipal solid waste incineration process

Event-triggered-based self-organizing fuzzy neural network control for the municipal solid waste incineration process