Mlonka-Mędrala, Agata
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inżynieria środowiska, górnictwo i energetyka
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Item type:Article, Access status: Open Access , Biomass thermochemical conversion via pyrolysis with integrated CO2 capture(2020) Sieradzka, Małgorzata; Gao, Ningbo; Quan, Cui; Mlonka-Mędrala, Agata; Magdziarz, Aneta
Wydział Inżynierii Metali i Informatyki PrzemysłowejThe presented work is focused on biomass thermochemical conversion with integrated $CO_{2}$ capture. The main aim of this study was the in-depth investigation of the impact of pyrolysis temperature (500, 600 and 700 °C) and $CaO$ sorbent addition on the chemical and physical properties of obtained char and syngas. Under the effect of the pyrolysis temperature, the properties of biomass chars were gradually changed, and this was confirmed by examination using thermal analysis, scanning electron microscopy, X-ray diffraction, and porosimetry methods. The chars were characterised by a noticeable carbon content (two times at 700 °C) resulting in a lower O/C ratio. The calculated combustion indexes indicated the better combustible properties of chars. In addition, structural morphology changes were observed. However, the increasing pyrolysis temperature resulted in changes of solid products; the differences of char properties were not significant in the range of 500 to 700 °C. Syngas was analysed using a gas chromatograph. The following main components were identified: $CO$, $CO_{2}$, $CH_{4}$, $H_{2}$ and $C_{2}H_{4}$, $C_{2}H_{6}$, $C_{3}H_{6}$, $C_{3}H_{8}$. A significant impact of $CaO$ on $CO_{2}$ adsorption was found. The concentration of $CO_{2}$ in syngas decreased with increased temperature, and the highest decrease occurred in the presence of $CaO$ from above 60% to below 30% at 600 °C.Item type:Article, Access status: Open Access , Potential of products from high-temperature pyrolysis of biomass and refuse-derived fuel pellets(2024) Jerzak, Wojciech; Mlonka-Mędrala, Agata; Gao, Ningbo; Magdziarz, Aneta
Wydział Inżynierii Metali i Informatyki PrzemysłowejThe management of energy contained in waste is an important research topic. Among many high-energy wastes, pellets are produced from refuse-derived fuels (RDF) and lignocellulosic biomass. This study investigated hightemperature pyrolysis (800 °C) of biomass and RDF pellets. Experiments were conducted in two reactors: i) on a microscale (thermogravimetric analysis) and ii) on a laboratory scale (fixed-bed reactor) to investigate the yields of the products (char, liquid fraction, and gas) and to characterise products toward their further application. The RDF char contained less carbon than the material before pyrolysis. The carbon content of the biomass char was 90%, almost twice that of the raw material. The biomass and RDF chars were chemically and physically activated to increase their specific surface areas. The chemically activated biomass char had a sorption capacity of 156.2 mg/CO2 at 25 °C and 0.1 MPa. The kinetics of CO2 sorption were also examined, and the maximum uptake was observed after 2–3 min. The higher heating value of the liquid phase, including the organic condensed phase, was 28.6 and 25.8 MJ/kg for pyrolysis of biomass and RDF pellets, respectively. The pyrolysis gas composition was analysed separately for the heating and isothermal processes. Due to the high CO, CH4, and H2 contents, the gas from the heating stage was characterised by a much higher heating value.Item type:Article, Access status: Open Access , Sustainable valorisation of waste-derived plastic rich materials into porous carbon materials for adsorption cooling applications(2025) Mlonka-Mędrala, Agata; Sieradzka, Małgorzata; Kalawa, Wojciech; Wu, Chunfei; Sowa, Marcin; Bujok, Tomasz; Magdziarz, Aneta
Wydział Inżynierii Metali i Informatyki Przemysłowej; Wydział Energetyki i PaliwThe thermochemical valorisation of waste materials rich in plastics offers a sustainable approach for waste reduction and the generation of high-value products, aligning with the European Green Deal and circular economy principles. This study investigates the conversion of three solid waste streams: refuse-derived fuel (RDF) from municipal (RDF_MW) and industrial (RDF_IW) sources and tyre-derived fuel (TDF) into activated carbons for application in adsorption cooling systems. A two-step activation process, combining pyrolysis at 600 °C with subsequent steam (850 °C) or chemical (KOH at 800 °C) activation, was employed to enhance porosity and surface area. RDF_IW-derived carbon activated with KOH achieved a maximum BET surface area of 955 m$^{2}$/g, while methanol adsorption tests showed an uptake exceeding 40 %. Heavy metal analysis revealed significant Zn contamination in TDF (up to 37,415 mg/kg), while Cr, Pb, and Sn were prominent in RDF samples; chemical activation reduced Zn content by up to 70 %. Performance testing in methanol-based adsorption chillers showed that RDF_IW_H2O and RDF_IW_KOH samples achieved specific cooling powers (SCP) of 53.5 W/kg and 88.9 W/kg, and coefficients of performance (COP) of 0.631 and 0.673, respectively, comparable to commercial activated carbons (CWH-22: SCP = 95.5 W/kg, COP = 0.615). These findings demonstrate the dual benefit of valorising heterogeneous waste into functional sorbents while enabling energy-efficient, low-grade thermal cooling systems.Item type:Article, Access status: Open Access , Pyrolysis of agricultural waste biomass towards production of gas fuel and high-quality char. Experimental and numerical investigations(2021) Mlonka-Mędrala, Agata; Evangelopoulos, Panagiotis; Sieradzka, Małgorzata; Zajemska, Monika; Magdziarz, Aneta
Wydział Inżynierii Metali i Informatyki PrzemysłowejBiomass 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.Item type:Article, Access status: Open Access , Pyrolysis of biomass wastes into carbon materials(2022) Sieradzka, Małgorzata; Kirczuk, Cezary; Kalemba-Rec, Izabela; Mlonka-Mędrala, Agata; Magdziarz, Aneta
Wydział Inżynierii Metali i Informatyki PrzemysłowejThis study presents the results of the biomass pyrolysis process focusing on biochar production and its potential energetic (as solid fuel) and material (as adsorbent) applications. Three kinds of biomass waste were investigated: wheat straw, spent coffee grounds, and brewery grains. The pyrolysis process was carried out under nitrogen atmosphere at 400 and 500 °C (residence time of 20 min). A significant increase in the carbon content was observed in the biochars, e.g., from 45% to 73% (at 400 °C) and 77% (at 500 °C) for spent coffee grounds. In addition, the structure and morphology were investigated using scanning electron microscopy. Thermal properties were studied using a simultaneous thermal analysis under an oxidising atmosphere. The chemical activation was completed using KOH. The sorption properties of the obtained biochars were tested using chromium ion $(Cr^{3+})$ adsorption from liquid solution. The specific surface area and average pore diameter of each sample were determined using the BET method. Finally, it was found that selected biochars can be applied as adsorbent or a fuel. In detail, brewery grains-activated carbon had the highest surface area, wheat straw-activated carbon adsorbed the highest amount of $Cr^{3+}$, and wheat straw chars presented the best combustion properties.Item type:Article, Access status: Open Access , Thermal upgrading of hydrochar from anaerobic digestion of municipal solid waste organic fraction(2022) Mlonka-Mędrala, Agata; Sieradzka, Małgorzata; Magdziarz, Aneta
Wydział Inżynierii Metali i Informatyki PrzemysłowejSolid fraction obtained from anaerobic digestion of municipal solid waste organic fraction is a waste produced in noticeable amounts, which according to circular economy concept can be upgraded to produce new, value-added products like: hydrogen rich process gas and carbon rich solid material. In this study, thermal upgrading of hydrochar by steam gasification was analysed. Raw material was obtained through hydrothermal carbonization (HTC) of digestate from anaerobic digestion of wet fraction of municipal solid waste at 200 and 230 °C, and residence time of 60 and 120 min. The further gasification step was carried out at 800 °C and the residence time was 10 min under nitrogen with a steam atmosphere. The main objective of hydrochar upgrading through steam gasification was production of carbon-rich material with developed active surface area. The study presented promising results regarding proper management of mixed wastes, which have not yet been analysed in the literature. It was noted that low temperature and residence time are favouring active surface area development. Analysis of the main gaseous products of the gasification process showed that syngas is composed mainly of $H_{2}$, $CH_{4}$, $CO_{2}$, $O_{2}$, and $CO$. The hydrogen concentration was the highest noted for hydrochar obtained at highest temperature and residence time. Analysis of the concentration of each syngas component reveals that combined treatment of digestate from anaerobic digestion through the HTC and gasification process results in $H_{2}$-rich syngas products and a high $H_{2}/CO$ ratio with parallel fair quality activated carbon.Item type:Presentation, Access status: Open Access , Marine plastic waste management according to circular economy concept through the interdisciplinary and international cooperationMagdziarz, Aneta; Wang, Jiawei; Wu, Chunfei; Sullivan, James; Mlonka-Mędrala, Agata
Wydział Inżynierii Metali i Informatyki PrzemysłowejGlobal plastic production is currently at a rate of 200,000 tonnes per year, and it is projected to increase to 33 billion tonnes per year by 2050. Approximately 10% of the plastic produced ends up in the seas and oceans. Plastic pollution in marine and coastal environments is a growing concern worldwide. Sources of this waste include shipping transportation, coastal tourism, marine aquaculture, and fishing. It is estimated that at least 14 million tonnes of plastic enter the oceans and seas annually. Furthermore, beach litter, which often consists of plastic packaging, lids, bottles, and cigarette butts, poses significant challenges. The G20 countries signed an Action Plan on Marine Litter in Germany in 2017, recognizing the urgent need to prevent and reduce marine litter to preserve human health as well as marine and coastal ecosystems. This highlights the need to reduce the amount of plastic waste in the sea, ocean, and coasts and find solutions to manage the existing waste. Proper management of marine waste can help stop the flow of waste in line with a closed-loop economy. Reducing and stopping plastic waste from reaching the oceans is crucial for achieving the UN Sustainable Development Goals (SDGs). The CUPOLA project is the international, interdisciplinary, and intersectoral research and innovation project aiming to find solutions to this global problem. The main goal of the CUPOLA project is to establish long-term research cooperation between institutions with complementary expertise to design and develop carbon-neutral, scalable, and socially acceptable methods to sort and convert plastic waste into valuable chemicals and materials. The originality of CUPOLA lies in the collaborative network among experimentalists, theoreticians, and industrialists. Key technologies in the project include waste sorting and pre-treatment methods. Novel pneumatic systems are developed for the separation of waste plastics, effectively separating the plastic waste into PET-rich, PO-rich, and PA-rich streams. The successful separation of plastic waste is crucial for the subsequent mechanical and chemical recycling processes. Thermochemical processes such as catalytic pyrolysis, catalytic gasification, aminolysis, and hydrothermal carbonization are applied to convert feedstocks into valuable chemicals and materials. For instance, the PET-rich stream will be transformed into bitumen additives through aminolysis, while the polyolefin-rich stream will be converted to benzene, toluene, and xylenes (BTX) via catalytic pyrolysis, and to H2 and carbon nanotubes through catalytic gasification. The project will involve process modeling, techno-economic analysis, and life cycle assessment to provide essential information about the economic viability and environmental impact of these processes. Additionally, renewable energy sources and carbon capture technologies will be integrated into the final design of the CUPOLA processes to ensure carbon neutrality. This project has the potential to bring together a wide range of research and industry groups in chemistry, chemical engineering, civil engineering, mechanical engineering, environmental science, and computer science to collaborate on the recycling of marine plastic waste. The success of the project will contribute to the achievement of Sustainable Development Goals (SDGs) 3, 12, and 14 by reducing plastic pollution in the oceans and converting waste into value-added products.