Kalemba-Rec, Izabela
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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 , Effects of asymmetric rolling with tilted material entry on texture and mechanical properties of aluminiumByrska-Wójcik, Dorota Joanna; Ostachowska, Monika; Gibek, Julia; Wierzbanowski, Krzysztof; Wróbel, Mirosław; Błoniarz, Remigiusz; Baczmański, Andrzej; Kopyściański, Mateusz; Kalemba-Rec, Izabela
Wydział Inżynierii Metali i Informatyki Przemysłowej; Wydział Fizyki i Informatyki Stosowanej; Wydział Fizyki i Informatyki StosowanejAsymmetric rolling texture of aluminium alloy 1050 was examined both experimentally and numerically. The rolling asymmetry was realized using rolls with different diameters rotating with the same angular velocity and by varying inclination of the rolling strip (i.e., the flat and tilted entry of the rolled strip between rolls). The final, 84% reduction in the thickness was obtained after six consecutive rolling passes. Crystallographic texture variation over the rolled bar thickness was determined using X-ray diffraction and predicted using the Finite Element Method combined with two crystalline deformation models (i.e., the elasto-plastic and the elasto-viscoplastic ones). Textures predicted by both models, taking into account all deformation process parameters, are in good agreement with experimental results. The obtained results confirm the effect of texture modifications caused by the shear stress component, resulting in the shifts of selected texture maxima in the orientation space, and explain the observed texture distribution across the sample depth. The novelty of this work consist in examination of the role of the tilted material entry (besides a difference in rolls diameters) in homogenization of texture distribution in multi-pass asymmetric rolling. The rolling geometry process variants, recommended for the technological practice, are indicated.Item type:Article, Access status: Open Access , Improvements in dewaterability and fuel properties of hydrochars derived from hydrothermal co-carbonization of sewage sludge and organic waste(2024) Wilk, Małgorzata; Śliz, Maciej; Czerwińska, Klaudia; Gajek, Marcin; Kalemba-Rec, Izabela
Wydział Inżynierii Metali i Informatyki PrzemysłowejThe hydrothermal co-carbonization of sewage sludge and organic additives, namely 10 and 20 % of charcoal, fir, grass, and an undersieved fraction of municipal solid waste, was studied. The benefits of this combined process included the spectacular dewaterability performance of slurry, proved by positive filtration tests and shorter capillary suction times. For instance, a 20 % fir addition decreased c.a. 60 % of pressure filtration time when compared to the hydrothermal carbonization of sewage sludge. A 10 % undersieved fraction of municipal solid waste resulted in 15.72 s of capillary suction time. Moreover, hydrothermal co-carbonization produced effective solid energy sources. The addition of organic origin waste to sewage sludge prior to the process caused higher heating values, carbon and fixed carbon contents of hydrochars (e.g. a 20 % charcoal addition generated 21 % higher heating value, 30 % carbon and 2.8 times higher fixed carbon), which corresponded with easier and more stable combustion processes compared to hydrochar from sewage sludge determined by thermal analysis. Possible exploitation problems during combustion have been assessed by determining the tendency risks of slagging and fouling based on oxides identified in ash by XRF analysis. Furthermore, changes in the structural and morphological properties of hydrochars were identified by SEM and FTIR analyses.Item type:Article, Access status: Open Access , Effect of pretreatment biomass by gas from polyvinyl chloride dehydrochlorination process on maize cob pyrolysis with integrated CO2 capture(2025) Jerzak, Wojciech; Kalemba-Rec, Izabela; Magdziarz, Aneta
Wydział Inżynierii Metali i Informatyki PrzemysłowejThis study investigates the effects of pretreatment of maize cob with hydrogen chloride gas obtained from polyvinyl chloride dehydrochlorination on pyrolysis yields and integrated CO₂ capture. The dehydrochlorination process was conducted at 320 °C, while the pyrolysis of the pretreated biomass was performed at 500 °C. Pretreatment significantly altered composition of biomass, reducing hemicellulose from 34.3 % to 3.7 %, increasing fixed carbon from 15.8 % to 20.3 %, and increasing the chlorine content from 0.27 % to 1.48 %. These changes influenced on the thermal decomposition characteristics of maize cob. During fast pyrolysis, the bio–oil yield increased by 17 %, from 32.9 % to 38.4 %, while gas production decreased from 38.7 % to 30.3 %, indicating a shift towards liquid biofuel production. Integration of calcium hydroxide in the pyrolysis reactor reduced CO₂ emissions by 87 %, from 56.5 % to 7.5 %, and captured chlorine from the pyrolysis gases, minimising harmful residues. Additionally, the use of calcium hydroxide facilitated the generation of hydrogen, increasing its content to 44.7 % in the gas phase. The bio–oil produced contained 0.8 % chlorine, demonstrating the effectiveness of in–situ chlorine capture. This approach, utilising hydrogen chloride derived from polyvinyl chloride waste, not only reduces environmental impact but also enhances the efficiency and sustainability of bio–oil production.