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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 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]

[Display omitted] • Pyrolysis technology can be successfully applied into RDF conversion. • Heating value of pyrolytic gas was estimated at the level about 24 MJ/m3. • Residence time significantly influences the pyrolytic gas composition. • Computer simulations predicted the chemical composition of pyrolytic gas. The current COVID-19 pandemic situation and the associated restrictions have increased the amount of generated waste. It results from the necessity to wear personal protective equipment. Thus, the disposal of masks and gloves is a topical issue and requires immediate investigation. The main aims of this work are management and environmental studies of municipal solid wastes (MSW), which have been generated during the COVID-19 pandemic time. Effective waste management in relation to a circular economy is presented. A sample of refuse derived fuel (RDF) with a high content of plastics was used for the experimental and calculation studies. Pyrolysis was selected as the best thermal decomposition process for this kind of wastes. Proximate and ultimate analyses were performed for RDF and its products. Pyrolysis was carried out using a pilot-scale reactor with a continuous flow of 250 kg/h at 900 °C. Thermogravimetric analysis was applied during the pyrolysis investigation and showed that the main decomposition of RDF took place in the temperature range of 250–500 °C. The pyrolysis gas contained combustible compounds like CO (19.8%), H 2 (13.2%), CH 4 (18.9%) and C 2 H 4 (7.1%), giving a high calorific value – 24.4 MJ/m3. The experimental results were implemented for numerical calculations. Chemkin-Pro software was applied to predict the chemical composition of the pyrolysis gas. The performed computer simulations demonstrated very good agreement with the results obtained during the experiments. They also indicated that there is a strong relationship between the chemical composition of the pyrolysis gas, the process temperature and residence time in the reactor. [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]

Abstract The main problem and also challenge was to find a satisfactory effective tool for real-time control the torrefaction/pyrolysis process of biomass and to evaluate (also in real-time conditions) biochar quality. This paper presents results from investigation on a new method for both evaluating biochar quality and control biomass thermal processing at temperatures of 300, 350 and 400 ◦ C. Thermal processing of biomass in this temperature range is torrefaction and pyrolysis. Investigation was focused on processing Virginia Mallow (Sida Hermaphrodita) energetic crops. Several strong correlations were observed as follows: carbon and hydrogen content in biochar (charcoal), oxygen content, ash and volatile matter from biochar, calorific value and temperature of the process and finally, acetic acid in condensate and carbon content in the biochar. The results show that the content of acetic acid, being one of the major compounds present in the condensate (black liquor, biooil), is in satisfactory linear correlation with the process temperature and furthermore, with carbon content in biochar. The mathematical description for this polynomial function was proposed as follows: Carbon (%) = 0.6e-3 x Acetic Acid (ppm)+49.5. The correlation between acetic acid in black liquor and carbon in biochar was used to introduce a new method which can be considered as a diagnostic tool for determining biochar quality in real-time conditions during biomass thermal processing. Hence, carbon content in biochar as well as its calorific value can be determined by measuring percentage of acetic acid in the condensate. This correlation was considered as the main novelty presented here. This method provides relatively fast evaluation of quality of biochar produced in industrial scale torrefaction systems, what makes it possible to optimize process parameters (temperature, retention time) in real time conditions and improve biochar production process in this way. Highlights • C H tradeoff for biochar is in strong linear negative correlation. • Acetic acid in biooil increased from 5 to 25% with process temperature increase. • Acetic acid in biooil is verifiable correlated with carbon content in biochar. • Acetic acid vs. carbon correlation can be used to control biochar quality. [ABSTRACT FROM AUTHOR]

The article presents the results of RDF (Refuse Derived Fuel) examination in order to use it for energy purpose. RDF material was subjected to thermogravimetric analysis. The TGA analysis confirmed the multi-component nature of tested material. It also indicated that the mixture consists of a minimum of 2 types of materials: biomass and thermoplastic polymers. The pyrolysis was conducted as a batch process with the use of a processing furnace supplied by the IZO Company. RDF sample was pyrolysed under 900 °C in a nitrogen atmosphere. Obtained char and gaseous sample, as well as raw material, were subjected to elemental and gas chromatographic analysis. Furthermore, using ANSYS CHEMKIN-PRO software, numerical simulations of these samples were conducted. Based on the results of composition of pyrolysis gas, the numerical model was validated. Next, modelling of chemical composition of gas from RDF pyrolysis for a pilot installation working in Poland was performed. In addition, the evaluation of the investment costs for the exemplary installation for the thermal conversion of RDF using pyrolysis was made. For this purpose, dynamic methods of investment project assessment were used, which take into account the distribution of anticipated revenues and expenses related to a given investment project over time. • Refuse Derived Fuel (RDF) can be a valuable energy source. • Thermal conversion of RDF by pyrolysis can contribute to limiting waste landfilling. • Calculations with the use of the ANSYS CHEMKIN-PRO software were conducted. • Economic analysis confirmed the legitimacy of the analysed investment. [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]

[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]