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Porosity of different rocks in relation to capturing/moving of gases and liquids
Řimnáčová, Daniela ; Vöröš, Dominik ; Natherová, Vendula ; Přikryl, R. ; Lokajíček, Tomáš
Variability in the porosity of natural rocks and waste have been investigated in relation to the influence on the\npermeability of gases and water. The samples were of sedimentary or igneous rocks, carbon-rich rocks, and solid\nporous waste material after thermal conversion. Using mercury intrusion porosimetry, porosity values and pore\nsize distribution varied with the origin of materials. These results have been compared and a connection between\nthe origin and porosity of material was observed. Total porosity values of selected samples ranged from ca. 0.2%\nfor granite to 55% for waste porous material. Lower porosity values demonstrate the connectivity between\nmesopores or micropores and are related to the capturing of greenhouse gases, while higher porosity is caused\npredominantly by the presence of macropores and coarse pores, which serve as pathways for permeability of\ngases and liquids.
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The processing of stabilized sewage sludge by high-temperature slow pyrolysis and gasification
Bičáková, Olga ; Čimová, Nikoleta ; Vöröš, Dominik ; Náhunková, Jana ; Řimnáčová, Daniela
One of the most challenging type of waste is sewage sludge, which is a heterogeneous suspension containing organic and inorganic substances and pathogenic organisms. This work focuses on an effective application method for the sewage sludge, which is usually deposited in landfills or co-incinerated in power plants. High temperature pyrolysis and gasification at 700–900 °C were applied to the samples of stabilized sewage sludge. The samples with a constant weight of 100 g were heated in a stationary bed, with the rate of batch heating being monitored. During the heating process, volatile products were released and the composition of the gaseous products developed during the heating was analyzed. Afterwards, the mass balance of the resulting products was evaluated. The elemental and textural analyses of the products were performed. Furthermore, it has been found that the solid residue has a porous texture and properties suitable for the removal and capture of pollutants. \n
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Three-dimensionally ordered micromesoporous carbon as adsorbent for CO2 capture
Vorokhta, Maryna ; Řimnáčová, Daniela ; Pilař, Radim
In this work, ordered three-dimensionally micromesoporous carbon composed of large spherical mesopores 13 nm in diameter and small micropores with a mean micropore width of 1.46 nm, connecting the main spheres, was synthesized and investigated for CO2 capture ability at temperatures of 25°C, 35°C and 50°C, and at pressures up to 6.5 MPa. Because of the big pore volume occupying 3.62 cm3/g, composed of mesopores and micropores, the carbon sample showed very high adsorption capacity at high pressures. The highest CO2 adsorption capacity of 24.03 mmol/g was obtained at 25°C and at 5.5 MPa. As the temperature increased, the CO2 adsorption capacity decreased to 13.34 mmol/g at 50°C and at 6.5 MPa. The Freundlich fittings of the measured adsorption isotherms at pressures up to 2 MPa showed very high correlation coefficients. The estimated isosteric heats of adsorption in the range of 5.62-6.90 kJ/mol indicated a physical adsorption process, and suggested a stronger interaction between CO2 molecules than between CO2 molecules and the surface of the carbon sample.
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Adsorption study of waste materials as potential adsorbents for pollutant removal and storage
Řimnáčová, Daniela ; Vorokhta, Maryna ; Vöröš, Dominik ; Borecká, Lenka ; Bičáková, Olga
The study shows how changing the experimental conditions during carbonization of a waste material such as sewage sludge influences textural properties and the CO2adsorption capacity of final carbonized productsin their potential use for removaland storage of pollutantssuch as carbon dioxide. The CO2adsorption measurements were done with gravimetric and manometric sorption devices in a wide range of pressures and temperatures. Further, CO2adsorption capacities of other materialssuch as activated carbon prepared from black carbon and a Czech Silurian shalewere compared toadsorption capacities of the studied carbonized sewage sludge. These two compared materials were chosen according to their compositionsand porosity.The porosityof the studied materials was determined from the N2sorption isotherms and measurements of their skeletal density with He.The adsorption capacity depended on the ratio of micropores and mesopores in the carbonized sewage sludge, because CO2fillsmicropores and mesopores at lowand highpressures, respectively, and was decreasing with the temperature increase atconstant pressure.The adsorption capacity of the carbonized sewage sludgewas increased by increase inthe carbonization temperature.The obtained adsorption capacities showed that the carbonization of sewage sludge can lead to preparation of perspective adsorbents for CO2capture and storage.
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Comparison of Particle Number Size Distributions in Three Central European Capital Cities
Zíková, Naděžda ; Borsós, T. ; Řimnáčová, Daniela ; Smolík, Jiří ; Wagner, Zdeněk ; Weidinger, T. ; Burkart, J. ; Steiner, G. ; Reischl, G. ; Hitzenberger, R. ; Schwarz, Jaroslav ; Salma, I. ; Ždímal, Vladimír
Health aspects of ultrafine aerosol particles in urban environment have been studied extensively in recent years (Salma et al., 2011; Putaud et al., 2010; Qian et al., 2007 etc.). Three main sources of the ultrafine particles have been defined – traffic, biomass burning, and atmospheric nucleation. However, the diurnal changes in intensities of individual sources are of considerable extent, similarly to the scale of variations in particle number concentrations due to meteorological phenomena.
Fulltext: content.csg -  PDF
Plný tet: SKMBT_C22013091814450 - PDF
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