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This article discusses the potential of using computer-simulation methods in processes such as thermal waste conversion, i.e., pyrolysis, gasification, combustion and torrefaction. These methods are gaining in importance, among others, due to the difficulties in execution and high costs associated with conducting experimental research in real conditions or the need to obtain detailed data on the phenomenon under study in a relatively short time. Computer simulation also allows for numerous errors to be avoided, such as those that may occur during optimization activities, the effects of which may have serious consequences, both economic and environmental. In addition to their many advantages, the limitations and disadvantages of using computer-simulation methods were also indicated, mainly related to the interpretation and validation of the results obtained using modelling. Owing to the complexity of the phenomena occurring during thermal conversion, special attention was focused on models based on chemical kinetics, thanks to which it is possible to predict the quantitative and qualitative composition of products in these processes. The aim of this research is to identify the research gap in the field of issues related to models of chemical kinetics of thermal waste conversion processes. [ABSTRACT FROM AUTHOR]

Poland is highly likely, as per a European Commission report, to fall short of meeting the 2025 targets related to the preparation for re-use and recycling of municipal waste and packaging waste. The risk of not meeting the municipal waste recycling targets stands at 27%, while for packaging waste, it is estimated at 30%. Recycling rates play a pivotal role in gauging the efficiency of waste management systems, as well as in monitoring progress toward a circular economy. Taking into account the considerable likelihood of Poland not achieving the recycling targets, the authors of the paper found it imperative to identify the risk factors associated with Poland's failure to meet the European Commission's recycling and landfill targets within the waste-to-energy context. Additionally, they sought to evaluate the potential for the development of the waste-to-energy concept in Poland. The research objectives were fulfilled through the literature review method. By employing the classification of factors outlined in a SWOT analysis, the authors highlighted which of the identified risk factors could or should be considered strengths or weaknesses, opportunities or threats to the Polish recycling process. Mapping out future courses of action will enable decision-makers in Poland to address the weaknesses in recycling, capitalize on opportunities arising from the socio-economic situation in Poland, and formulate plans to mitigate the identified threats. Undertaking such initiatives has the potential to enhance recycling rates in Poland and facilitate the broader application of waste-to-energy practices. [ABSTRACT FROM AUTHOR]

The main goal of the study was to assess the possibility of practical use of products of pyrolysis of refuse-derived fuel (RDF), i.e., pyrolysis gas, biochar and pyrolysis oil, as an alternative to standard fossil fuels. The subject matter of the paper reaches out to the challenges faced by the global economy, not only in the context of the energy crisis, but also in the context of the energy transformation currently beginning in Europe. The increase in fuel and energy prices prompts countries to look for alternative solutions to Russian minerals. At the same time, the growing amount of municipal waste forces the implementation of solutions based on energy recovery (the amount of municipal waste per EU inhabitant in 2021 is 530 kg). One such solution is pyrolysis of RDF, i.e., fuels produced from the over-sieve fraction of municipal waste. In Poland, insufficient processing capacity of thermal waste conversion plants has led to significant surpluses of RDF (1.2 million Mg of undeveloped RDF in Poland in 2021). RDF, due to their high calorific value, can be a valuable energy resource (16–18 MJ/k). This issue is analyzed in this study. [ABSTRACT FROM AUTHOR]

This review presented a comprehensive analysis of recent developments in research regarding the use of lignocellulosic biomass products in the iron and steel industry. The role of lignocellulosic biomass used as a source of energy as well as reducing agents in iron and steel sector in the era of energy crisis served as the foundation for this review. Attention has been paid to different biomass characteristics as well as pretreatment methods and conversion products of biomass. The present review also included some issues of energy management system in the steel industry. Furthermore, the possibilities of replacing fossil energy carriers with lignocellulosic biomass in the steel and iron industry was reviewed focusing on advantages, challenges, and future prospects. The present process and product quality criteria, which biomass-derived fuels must also meet, was discussed. This paper compiled the most current developments in biomass metallurgical research to serve as a source for the theoretical foundation as well as for the development of practical applications. The novelty of this study lies in the comprehensive discussion of the lignocellulosic biomass application in the iron and steel industry that are so far unpublished. [ABSTRACT FROM AUTHOR]

One of the greatest challenges humankind currently faces is global warming, mainly caused by greenhouse gas emissions. Here we have attempted to show how thermal conversion products, specifically from the pyrolysis of biomass wastes such as sewage sludge, can be used effectively and equivalently to sequester CO2 in brownfield and degraded areas. Scenarios were devised that showed the significant potential for CO2 sequestration in the form of biochar from sewage sludge deposited on degraded and brownfield areas. With the current amount of sludge production, such sludge could even be used in its entirety as a raw material in pyrolysis processes, where, in addition to the biochar, the heat necessary for drying the sludge could be generated and high-energy gas and liquid fractions could be obtained, which could be used to produce alternative fuels. It is therefore important to consider both the potential for CO2 sequestration on degraded and brownfield sites and the potential for sludge disposal in Europe as viable options for reducing greenhouse gas emissions and promoting sustainable waste management practices. [ABSTRACT FROM AUTHOR]

This review comprehensively examines biochar, an essential material in an era of climate change for reducing carbon dioxide (CO2) emissions into the atmosphere. It is inconspicuous, black, lightweight, and very porous, and is produced through the thermal conversion of biomass. Our literature review highlights biochar's expansive application possibilities. Firstly, its potential to improve soil quality and sequester CO2 has been examined, as well as its utilization in iron and steel manufacturing to minimize the quantity of coke and ultimately reduce CO2 emissions. In industrial manufacturing, the complete elimination of coke can promote environmental neutrality, which is achieved using biochar from biomass for its extrusion. Furthermore, biochar is becoming increasingly significant in modern energy storage technologies and as an important additive in Pickering emulsions, which are also employed in energy storage systems. Additionally, the use of carbon black is a broad topic, and this review illustrates where it can be successfully utilized, especially in environmentally sensitive areas. [ABSTRACT FROM AUTHOR]

The aim of the article is to analyse the impact of selected conditions on the use of municipal solid waste in energy production processes. The authors in this publication indicated that the factors determining the effective use of solid municipal waste may be, in particular, formal and legal conditions, methods used in the processes of thermal waste transformation, recovery logistics or emergency situations such as pandemics or armed conflicts. Their knowledge can be very useful in the processes of the effective use of municipal waste for the production of thermal energy, especially in the current period of the energy crisis faced by most EU countries. This paper also emphasizes the importance of RDF (refuse-derived fuel) for the thermal energy sector, which can be used both in large combustion plants and in less powerful facilities, including local heating and combined heat and power plants as an alternative to traditional fossil fuels. The article was prepared by means of the systematic literature review (SLR) method, utilising the Scopus database and secondary sources. [ABSTRACT FROM AUTHOR]

The aim of the article is the offer of control of environmentally undesirable products of coal and biomass co-firing with the use of numerical methods. The article analyzes the impact of co-combustion of coal and pellets made of sunflower husk in power plant boiler with a capacity of 125 MW on the composition of the flue gas. Based on the data obtained from a real object, in particular: the combustion temperature, the reagent fluxes, i.e. air, coal and biomass, as well as the elemental composition of the fuels supplied into the boiler, the initial conditions were formulated and the computer simulations were made, leading to determining the chemical composition of flue gas. Numerical calculations were performed using the latest version of CHEMKIN-PRO software. Chemical mechanism was developed by the Italian group The CRECK Modeling and it included 134 compounds and 4169 chemical reactions, including reactions of forming chlorine compounds. Additionally, the impact of selected parameters, e.g. temperature on the chemical composition changes of the combustion products was analyzed. Developed calculation model with the implemented chemical mechanism was verified by data collected from the real conditions, leading to increasing the reliability of the results. The calculations showed that the most important influence on the composition of the flue gas from the co-firing process of coal with sunflower husk has a composition of biomass. It should be emphasized that the results of computer simulations obtained by the authors have an useful aspect and can be applied in practice, especially to the analysis of the mechanism of chloride corrosion which is possible to occur due to the chlorine content in the biomass. They may also be useful for evaluating the unburned hydrocarbons produced by combustion of rich mixtures (λ < 1.0).

In recent years the numerical modelling of biomass combustion has been successfully applied to determine the combustion mechanism and predict its products. In this study the influence of the addition of waste glycerin in biomass wood pellets on the chemical composition of exhaust gases has been investigated. The pellets have been prepared from spruceand pine wood sawdust without and with addition of waste glycerin. The waste glycerol is a undesirable by-product of biodiesel transesterification at oil manufacturing. The produced pellets were being burned in the 10 kW domestic boiler adapted to wood pellets combustion. The possibilities of pollutants generation (CO2, CO, NOx SOx and compounds containing chlorine) in the exhaust gases coming from the boiler were numerically calculated using the latest version of CHEMKIN-PRO software, introduced by the American company Reaction Design. The results of the calculations correspond to the data obtained on a real object, in particular: combustion temperature, gas pressure, residence time of fuel in the burner, air flow, fuel consumption, as well as elementary composition of fuel supplied into the boiler. The proposed method of predicting the chemical composition of exhaust gases allows proper control of the combustion process and can be considered as an important step in reducing the pollutants (lower emission of NOx, SOx and CO2 neutral) and thus to contribute to the improvement of the environmental quality. In addition, knowledge of the amounts of Clbased compounds produced in combustion process (under given conditions), can serve as an important hint in terms of corrosion prevention of boiler- and chimney steels.

This paper presents an assessment of the impact of the COVID-19 pandemic on the waste management sector, and then, based on laboratory tests and computer calculations, indicates how to effectively manage selected waste generated during the pandemic. Elemental compositions—namely, C, H, N, S, Cl, and O—were determined as part of the laboratory tests, and the pyrolysis processes of the above wastes were analysed using the TGA technique. The calculations were performed for a pilot pyrolysis reactor with a continuous flow of 240 kg/h in the temperature range of 400–900 °C. The implemented calculation model was experimentally verified for the conditions of the refuse-derived fuel (RDF) pyrolysis process. As a result of the laboratory tests and computer simulations, comprehensive knowledge was obtained about the pyrolysis of protective masks, with particular emphasis on the gaseous products of this process. The high calorific value of the pyrolysis gas, amounting to approx. 47.7 MJ/m3, encourages the management of plastic waste towards energy recovery. The proposed approach may be helpful in the initial assessment of the possibility of using energy from waste, depending on its elemental composition, as well as in the assessment of the environmental effects. [ABSTRACT FROM AUTHOR]

Our paper investigates the problems of co-combustion of select grades of biomass, i.e. hay, straw, and wood waste, with natural gas. Research comprised both a laboratory experiment and numerical simulations with the use of a professional software application, Chemkin-Pro. The chemical mechanism of co-combustion of biomass with natural gas was described using 224 reactions and 56 chemical compounds. Based on the flow data determined on an experimental stand, the initial conditions were formulated and numerical simulations were performed. As a result of numerical simulations, the detailed chemical composition of combustion gas at the heating chamber outlet was obtained. The investigation has shown that the use of biomass for energy perposes significantly contributes to the reduction of pollutant emissions in flue gas. [ABSTRACT FROM AUTHOR]

The paper presents the results of experiments on the effect of carbon dioxide addition during natural gas air combustion on the concentrations of CO and NOx in the combustion chamber. Numerical simulations were also performed using the Chemkin-Pro program. As part of the presented experiments, an innovative method of introducing carbon dioxide through the central nozzle of a kinetic burner was tested. This technique allows CO2 to be fed directly into the high-temperature zone, thus not hindering the mixing of the fuel with the oxidizer. The tests were carried out for an excess combustion air ratio of λ=1.1, 1.15 and 1.2, respectively, during the addition of CO2 to 15% vol. of oxidizing mixture (air + carbon dioxide). From combustion gas analyses made at a distance of 740mm from the burner outlet in the furnace axis and 20 and 40 mm from the axis, it was found that combustion chamber CO concentrations depended on the amount of CO2 introduced, the distribution of CO2 in the combustion chamber cross-section associated with the CO2 addition method and the excess air ratio. The highest CO concentrations were only noted in the combustion chamber axis with a considerable fraction of added CO2. Based on the computations and experiments it has been confirmed that diluting combustion gas with CO2 delivers a reduction in NOx concentrations. [ABSTRACT FROM AUTHOR]

This paper contains experimental research of NOxreduction in the combustion process with the primary methods, which were applied separately and in combined systems. In addition, the pulsation disturbance (PD) was applied, that is the gas stream was disturbed to increase the intensity of reagents mixing. An experimental stand was built to determine an influence of the following primary methods: air staging, reburning and flue gas recirculation on a reduction of NOxconcentration. Experiments were carried out in three combinations: air staging with reburning, reburning with recirculation and air staging with recirculation. In all these cases, the PD was simultaneously applied. Researches were carried out in a quartz combustion chamber with laboratory equipment enabled to measure all the thermal and the chemical parameters of the process. The simultaneous application of primary methods causes additional increase in NOxreduction in certain systems. [ABSTRACT FROM AUTHOR]

This article presents the results of numerical calculations of chemical composition of flue gas produced by combustion of natural gas in an industrial heating device, i.e., a pusher furnace. In calculations of combustion chemistry, the CHEMKIN-PRO program was used. The gas-dynamic of flue gas was modeled with the use of the COMSOL Multiphysics program. In order to check the correctness of the plug flow reactor (PFR) model, as applied in calculations, a preliminary laboratory experiment was conducted. Based on measurement data that were obtained during the research on a laboratory stand, the boundary conditions were formulated and numerical simulations were carried out. The temperature and velocity profiles in the combustion chamber were determined with the use of the COMSOL program and were implemented in the CHEMKIN program. The obtained results of the numerical simulations performed in the experimental chamber showed high compliance with the results of measurements. This, in turn, led us to apply the analysis on a real object. The simulations of the chemical composition of flue gas in the each zone of the furnace were carried out based on the measurements data collected from the real object, i.e., a pusher furnace that is currently working in one of the steel plants located in our country. [ABSTRACT FROM AUTHOR]

Poland's management of municipal waste, which amounts to over 13 million tons/year, is not efficient—about 60% of the waste is subjected to recovery processes, about 20% of all municipal waste is converted into energy, and almost 40% is landfilled. The authors of this article recognize the potential of pyrolysis as a method of the thermal processing of waste allowing the potential of the energy contained in the waste to be utilized. Pyrolysis is an economically attractive alternative to incineration, with a significantly lower environmental impact, allowing efficient waste management and the use of pyrolysis by-products in the energy sector (pyrolysis gas), or in the building materials sector (biochar). Despite so many advantages, this method is not employed in Poland. The aim of the paper is to indicate a recommended strategy for the application of pyrolysis in Poland as a method of the thermal processing of municipal solid waste. SWOT (strengths, weaknesses, opportunities, threats) analysis was used as a research method. In the first step, on the basis of the literature review, the factors which may affect the use of pyrolysis in Poland were identified. In the second step, five experts evaluated the weights of those factors and the interactions between them. The products of the weights and interactions allowed, in accordance with SWOT analysis methodology, the most desirable strategy of pyrolysis application in Poland to be determined, which turned out to be an aggressive one. This means that pyrolysis as a thermal waste processing method should be implemented on a large scale in Poland to improve the indicators of municipal waste management. [ABSTRACT FROM AUTHOR]

The article presents the possibilities of effective management of lignocellulosic waste by including it in the circular economy. The pyrolysis process was chosen as the thermal conversion method. This approach, due to a high flexibility of the obtained products, better quality of the solid residue (char), and the lower emission of pollutants into the atmosphere, e.g., SO2 and NOx, is a competitive solution compared to combustion process. Wood waste from alder and pine were analyzed. As part of laboratory tests, the elementary composition was determined, i.e., C, H, N, S, and O. The pyrolysis process was carried out at a temperature of 600 °C on an experimental stand for the conversion of solid fuels in a stationary bed. For the obtained data, using the Ansys Chemkin-Pro calculation tool, the detailed chemical composition of gaseous products of the pyrolysis process was modeled for a varying temperature range and residence time in the reactor. The studies have shown that for certain process conditions it is possible to obtain a high calorific value of pyrolytic gas, up to 25 MJ/m3. [ABSTRACT FROM AUTHOR]

The paper evaluates the possibility of efficiently processing waste generated in the process of biomass torrefaction into a non-toxic material, suitable for practical reuse. The water was evaporated from the liquid fraction resulting from the torrefaction of Virginia mallow, after which the resulting sludge was subjected to vitrification. The vitrification process was carried out at 1450 °C using tempered glass cullet, which constituted 85% by weight of the total processed material. The obtained product was subjected to the following analyses: microstructural characterization, X-ray diffraction, energy dispersive spectroscopy, spectroscopic tests, as well as measurements of hardness and ion leachability in an aqueous medium. It was found that vitrification of the sludge obtained from the waste liquid fraction leads to incorporation of the inorganic components of the waste into the glass structure, and in the case of organic components, causes their thermal decomposition. As a result of vitrification, a product was obtained that has no toxic properties and is characterized by favorable utility properties, i.e. low ion leachability and high hardness, higher than the hardness of the glass used in the vitrification process. The conducted research showed that vitrification is an effective method to recycle waste generated in the production process of treated biomass, and the product of the vitrification process can be used, for example, in the production of glassy building materials. • Wastes generated during biomass torrefaction can be effectively vitrified. • Vitrification process converts biomass torrefaction waste into a harmless product. • Vitrificat is amorphous and characterised by high hardness and low ion leachability. • Vitrification may be an alternative to other waste disposal techniques. [ABSTRACT FROM AUTHOR]

As known, dried sewage sludge, is a by-product produced from waste water treatment, contains significant amounts of organic content, and makes up to 60% with overall calorific value from 9 to 12 MJ/kg. Hence, it can be considered as material for thermal processing focusing on heat and power production. Among thermal conversion technologies, gasification is seen as the effective one because it can be easily combined with heat and power cogeneration units. On the other hand, due to high mineral content (40–50%) in the sludge, it is difficult to be gasified and obtain syngas with calorific value satisfactory enough for fueling the internal combustion engine. The dried sludge can be subjected to be gasified at temperature above 850 °C. However, large amounts of mineral content do not provide favorable conditions to obtain this required temperature. Thus, it is proposed to enrich the sewage sludge with biomass characterized with significantly higher calorific value. In the article, co-gasification of sewage sludge and Virginia Mallow—energetic crops was investigated. Results from experimental and numerical investigation have been presented. The dried sewage sludge enriched with Virginia Mallow at a mass ratio of 0/100%, 50/50% and 100/0% in tests and in the range from 0 to 100% for theoretical analysis was applied in order to achieve effective gasification process. As observed, lignocellulosic biomass like Virginia Mallow contains low amounts of mineral content below 2%, which makes it appropriate for thermal processing. It contributes to more stable and efficient gasification process. Additionally, Virginia Mallow caused that the process temperature possible to achieve, was 950 °C. Thus, sewage sludge was mixed with this high-energy component in order to improve the gasification parameters and obtain syngas with higher calorific value. A zero-dimensional, two-zone model was developed with aid of the POLIMI kinetics mechanism developed by CRECK Modeling Group to simulate gasification of low calorific substances enriched with high calorific biomass. Obtained results showed that sewage sludge can be completely gasified at presence of Virginia Mallow. Syngas calorific value of approximately 5 MJ/Nm3 was produced from this gasification process. The maximal percentage of Virginia Mallow in the mixture with the sewage sludge was set at 50% due to economic aspects of the technology. It was found, that satisfactory conditions for effective gasification were achieved at this 50/50% percentage of sewage sludge and Virginia Mallow. Potential intensity of gasification was predicted from this 0-D 2-zones model, which calculates area of reduction zone to area of combustion zone. This reduction-to-combustion area ratio for the sewage sludge-Virginia Mallow mixture was estimated at value of 2. Finally, the model was successfully verified with results from tests, hence it was proposed as a tool for preliminary investigation on poor fuels gasification. [ABSTRACT FROM AUTHOR]

There can be observed global interest in waste pyrolysis technology due to low costs and availability of raw materials. At the same time, there is a literature gap in forecasting environmental effects of thermal waste treatment installations. In the article was modelled the chemical composition of pyrolysis gas with main focus on the problem in terms of environmental hazards. Not only RDF fuel was analysed, but also selected waste fractions included in its composition. This approach provided comprehensive knowledge about the chemical composition of gaseous pyrolysis products, which is important from the point of view of the heterogeneity of RDF fuel. The main goal of this article was to focus on the utilitarian aspect of the obtained calculation results. Final results can be the basis for estimating ecological effects, both for existing and newly designed installations. Pyrolysis process was modelled using Ansys Chemkin-Pro software. The investigation of the process were carried out for five different temperatures (700, 750, 800, 850 and 900 °C). As an output the mole fraction of H 2 , H 2 O, CH 4 , C 2 H 2 ,C 2 H 4 , C 3 H 6 , C 3 H 8 , CO, CO 2 , HCl and H 2 S were presented. Additionally the reaction pathways for selected material were presented. Based on obtained results, it was established that the residence time did not influenced on the concentration of products, contrary to temperature. The chemical composition of pyrolytic gas is closely related to wastes origin. The application of Chemkin-Pro allowed the calculation of formation for each products at different temperatures and formulation of hypotheses on the reaction pathways involved during pyrolysis process. Further, based on the obtained results confirmed the possibilities of using pyrolysis gas from RDF as a substitute for natural gas in energy consumption sectors. Optimization of the process can be conducted with low financial outlays and reliable results by using calculation tools. Moreover it can be predicted negative impact of obtained products on the future installation. [ABSTRACT FROM AUTHOR]

The study assessed the possibility of using waste glass cullet from the screen part of CRTs (cathode ray tube) in the vitrification of asbestos-cement materials (ACM). The composition consisting of 50% by mass ACM and 50% by mass cullet was subjected to vitrification. The research material before and after vitrification was subjected to comparative analysis. As a result of vitrification, a transparent amorphous material was produced with a hardness about 7% higher than that of CRT glass and lower ion leachability in an aqueous environment compared to ACM. X-ray and spectroscopic examinations did not reveal the presence of chrysotile, i.e. a type of asbestos found in ACM. This fact proves that during vitrification the asbestos decomposed and formed a lattice of glass composed of the products of this decomposition. Moreover, the presence of heavy metals in the vitrified product was found, including Ba and Sr, the source of which was the CRT cullet. The obtained research results prove that ACM vitrification with CRT cullet leads to the effective utilization of both types of waste during one technological process. Therefore, the vitrification of ACM can be successfully carried out using waste CRT glass, and the harmless product obtained in the vitrification process can be used in practice. The use of CRT cullet in the vitrification of asbestos-cement materials will also have a positive impact on the environment as it will reduce the amount of electronic waste deposited in landfills. [Display omitted] • The vitrification of ACM can be successfully carried out using CRT glass cullet. • It is possible to simultaneously dispose of ACM and CRT cullet in one process. • The vitrification process transforms the hazardous wastes into a harmless product. • Vitrification is an effective method of neutralizing asbestos-cement materials. • The vitrification process leads to the complete decomposition of chrysotile. [ABSTRACT FROM AUTHOR]

[Display omitted] • A study of oat straw pyrolysis was performed at various temperatures. • Multifaceted analysis of gas, liquid and solid phases was carried out. • Pyrolytic gas quality increased with temperature. • Chemkin modelling of pyrolysis allowed to predict chemical composition of syngas. Biomass wastes are sustainable, renewable, and promising energy sources. In this study, the pyrolysis of agricultural biomass was investigated to determine the most promising process parameters for pyrolytic gas production. The pyrolysis investigations were carried out under nitrogen atmosphere at 300, 400, 500, and 600 °C on the microscale using simultaneous thermal analysis and a laboratory-scale semi-batch vertical reactor. The solid, liquid, and gaseous products were characterised in detail, including the elemental and chemical composition. The gas and liquid products analyses were provided. It was found that the quality of the pyrolytic gas increased with temperature, both in terms of the pyrolytic gas yield and concentration of gaseous components (hydrogen and methane), whereas the carbon dioxide concentration decreased with temperature. The condensed vapours were rich in phenolic and aromatic compounds, and it was noted that the acetic acid concentration increased with temperature. The chemical functional groups in the char were determined using infrared spectroscopy. The carbon content increased with temperature, whereas the hydrogen content decreased. Further decomposition of the organic matrix was observed with increasing temperature. Additionally, chemical modelling of pyrolytic gas was performed using Ansys Chemkin-Pro software and compared with the experimental results. The computational results showed a good correlation with the measured pyrolytic gas composition, especially in the case of the major gas components. [ABSTRACT FROM AUTHOR]