Publications by authors named "Tadeusz Dziok"

4 Publications

  • Page 1 of 1

Possibility of using alternative fuels in Polish power plants in the context of mercury emissions.

Waste Manag 2021 May 14;126:578-584. Epub 2021 Apr 14.

AGH University of Science and Technology, Faculty of Energy and Fuels, Al. A. Mickiewicza 30, 30- 059 Krakow, Poland.

The progressive decarbonisation of industry is leading to a reduction in coal consumption and the substitution for coal with other types of fuels, including waste-derived alternative fuels. These fuels are characterised by high variation in the content of highly toxic mercury. Co-combustion with coal can cause significant emissions, exceeding mercury emission limits. Various alternative fuels (refuse-derived fuel (RDF), waste paper, textiles, plastics, film, tires and their char, and sewage sludge) were examined for mercury content. The mercury content in analysed alternative fuels ranged from 0.4 to 92.0 µg Hg/MJ, with an average of 17.7 µg Hg/MJ. The fuels with the highest mercury content were RDFs (2.0-79.3 µg Hg/MJ) and sewage sludge (42.3-92.0 µg Hg/MJ). An acceptable amount of RDF added to hard coal which would remain within the emission limits was estimated to be 9-24% of the chemical energy in the blend. For sewage sludge, this amount was estimated to be 5-13%. For brown coal, with a much higher mercury content than hard coal, co-combustion with alternative fuels has a positive effect on reducing mercury emissions. It is possible to meet the mercury emission limits with a 95% contribution of the chemical energy coming from RDF. The blending of various types of waste supported by mild pyrolysis of high-mercury waste allows alternative fuels with relatively low mercury content to be produced. Such fuels may contribute a reduction in mercury emissions from coal-fired power plants in Poland.
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http://dx.doi.org/10.1016/j.wasman.2021.03.053DOI Listing
May 2021

Synthesis and Characterization of Halloysite/Carbon Nanocomposites for Enhanced NSAIDs Adsorption from Water.

Materials (Basel) 2019 Nov 14;12(22). Epub 2019 Nov 14.

AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Kraków, Poland.

The adsorption of ketoprofen, naproxen, and diclofenac (non-steroidal anti-inflammatory drugs, NSAIDs) on halloysite/carbon nanocomposites and non-modified halloysite were investigated in this work. Halloysite/carbon nanocomposites were obtained through liquid phase impregnation and carbonization using halloysite as the template and saccharose as the carbon precursor. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectrometry (FT-IR), and low-temperature nitrogen adsorption method were employed to study the morphological and structural changes of the halloysite/carbon nanocomposites. The effects of contact time, initial concentration of adsorbates, pH of solution, and mass of adsorbent on the adsorption were studied. Adsorption mechanism was found to fit pseudo-second-order and intra-particle diffusion models. The obtained experimental adsorption data were well represented by the Langmuir multi-center adsorption model. Adsorption ability of halloysite/carbon nanocomposites was much higher for all the studied NSAIDs in comparison to non-modified halloysite. Optimized chemical structures of ketoprofen, naproxen, and diclofenac obtained by Density Functional Theory (DFT) calculation showed that charge distributions of these adsorbate molecules and their ions can be helpful to explain the details of adsorption mechanism of NSAIDs on halloysite/carbon nanocomposites.
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http://dx.doi.org/10.3390/ma12223754DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6887771PMC
November 2019

Assessment of mercury emissions into the atmosphere from the combustion of hard coal in a home heating boiler.

Environ Sci Pollut Res Int 2019 Aug 31;26(22):22254-22263. Epub 2019 May 31.

Faculty of Energy and Fuels, AGH University of Science and Technology, Al. A. Mickiewicza 30, 30-059, Krakow, Poland.

The purpose of the paper was to determine the factor of mercury emission into the atmosphere by households in Poland. Research for a home coal-fired boiler typical of Polish conditions was carried out, which was conducted throughout the heating season. On the basis of assessment of the quantity of coal burned and mercury content contained therein, as well as of the mercury content in bottom ash, chimney soot, boiler deposits and their quantities, annual mercury emissions and its factor of emission into the atmosphere were defined. It was defined that the mercury emission factor for the investigated case of a single-family house is at a level of 0.56 μg/MJ. It was shown that 41.4% of the mercury contained in coal burned in a home heating boiler is emitted into the atmosphere, 57.0% is adsorbed by chimney soot, 0.3% by boiler heater deposits and 1.3% passes into bottom ash. Annual mercury emissions into the atmosphere from the single-family house concerned was 79 mg. Mercury emissions can be significantly reduced by households by separating any overgrowths with pyrite from coal. The solution proposed would enable a reduction in annual mercury emissions into the atmosphere in Poland from the domestic user sector by 58.5% (0.351 Mg). The factor of emission of mercury into the atmosphere would be 0.23 μg/MJ.
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http://dx.doi.org/10.1007/s11356-019-05432-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6658574PMC
August 2019

Studies on mercury occurrence in inorganic constituents of Polish coking coals.

Environ Sci Pollut Res Int 2019 Mar 12;26(9):8371-8382. Epub 2018 Mar 12.

Faculty of Geology, Geophysics and Environmental Protection, AGH University of Science and Technology, Al. A. Mickiewicza 30, 30-059, Krakow, Poland.

During the cokemaking process, a significant amount of mercury occurring in a coal blend is released to the atmosphere. One of the ways of reducing this emission is to reduce mercury content in a coal blend. This could be obtained through the coal washing process. The optimization of this process requires the knowledge of mercury occurrence in coal, especially in its inorganic constituents. A qualitative analysis of mercury occurrence in the inorganic constituents of Polish coking coals was performed using an electron probe microanalyzer (EPMA). For that purpose, selected samples of rejects and middling products derived from the washing process in dense media separators and jig concentrators were examined. The obtained results have confirmed a strong connection between mercury occurrence and the presence of sulfides (pyrite, marcasite, and chalcopyrite) in Polish coking coals. Significant amounts of mercury were also noticed for barite, siderite, and aluminosilicates. The highest value of mercury content, at the level of 0.100%, was obtained for marcasite. For the analyzed coals, the effectiveness of mercury removal in the washing process was determined by the forms of pyrite occurring in coal. The highest values of effectiveness of mercury removal were obtained in the case of coals for which the large framboidal pyrite aggregates with chalcopyrite overgrowths were noticed. It was also found that middling products were characterized by the occurrence of the Hg-rich overgrowths of pyrite on organic matter. To achieve a significant reduction in mercury content in clean coal, it is necessary to develop an effective method of removing this form of pyrite from hard coal.
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http://dx.doi.org/10.1007/s11356-018-1667-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6469601PMC
March 2019
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