Browsing by Subject "catalyst"

Now showing 1 - 4 of 4

Access status: Open Access ,
Możliwości redukcji tlenków azotu z gazów spalinowych maszyn górniczych
(Wydawnictwa AGH, 2005) Szlązak, Nikodem; Szlązak, Justyna
This article presents the method of Selective Catalytic Reduction as an example of usage in nitrogen oxides decomposition to molecular nitrogen and oxygen. The review is mainly focused on the description of the catalytic properties of CoZSM-5 in selective catalytic reduction (CH4-SCR) of nitrogen oxides. Due to EPR and UV-VIS researches speciation of cobalt ion in ZSM-5 matrix was described and TOF analyses helped to characterize the most active catalytic center. Furthermore, the mechanism of the NOx reduction and the formation of Co dinitrosyl complexes, as an important intermediate in SCR reaction, was presented.
Access status: Open Access ,
Porowate heterostruktury ilaste (PCH) na osnowie montmorillonitu jako selektywne katalizatory
(2007) Strycharczyk, Marta
Access status: Open Access ,
The effect of an acid catalyst on the hydrothermal carbonization of sewage sludge
(2023) Wilk, Małgorzata; Śliz, Maciej; Czerwińska, Klaudia; Śledź, Małgorzata
This research is focused on the addition of a catalyst, sulphuric acid (VI), to sewage sludge, and its effect on solid and liquid products resulting from the hydrothermal carbonization process. Consequently, for hydrochars, proximate and ultimate analyses, higher heating value and specific surface area were determined. Additionally, Fourier-transform infrared spectrophotometric and thermogravimetric analyses were conducted. The heavy metal contents in the ash composition of hydrochars were identified by X-ray fluorescence spectrometry. It was confirmed that the catalyst addition changed the structure as well as the physical and chemical properties of hydrochars and their ashes. Regarding post-processing water, both pH value and conductivity were determined and the element composition, including heavy metals, was conducted by the inductively coupled plasma optical emission and mass spectrometry analyses. It was found that the addition of the catalyst caused a decrease in heavy metal contents and an increase of phosphorus compound in filtrates.
Access status: Open Access ,
Valorisation of tyre waste from a vulcanisation plant by catalytic pyrolysis – Experimental investigations using pyrolysis–gas chromatography–mass spectrometry and drop-tube–fixed-bed reactor
(2024) Jerzak, Wojciech; Wądrzyk, Mariusz; Sieradzka, Małgorzata; Magdziarz, Aneta
Wydział Inżynierii Metali i Informatyki Przemysłowej
This study focuses on the use of car tyre waste collected at a tyre repair station in Krakow (Poland). Waste from damaged tyres is disposed of as municipal solid waste. Therefore, the management of waste tyres already shredded by pyrolysis at 500 °C has been proposed. Tyre waste was hypothesised to be converted into valuable chemical products by pyrolysis in a hybrid reactor (drop-tube–fixed-bed reactor). On a micro scale, pyrolysis–gas chromatography–mass spectrometry was used to analyse the pyrolysis process. It has been shown that the formation of aromatic hydrocarbons during pyrolysis clearly depends on whether the catalyst and tyre waste are mixed together or arranged in layers. Since the layered arrangement favoured the formation of hydrocarbons, such a system was used in the drop-tube–fixed-bed reactor. The high heating rate (500 °C/s) of tyre particles in the drop-tube–fixed-bed reactor at 500 °C allowed for the obtained a raw carbon black yield of 40.8 %. A similar yield of raw carbon black determined by thermogravimetric analysis for a heating rate of 0.17 °C/s) was observed at 800 °C. However, before commercial use, raw carbon black requires demineralisation because of its high ash content (approximately 50 %). The raw carbon black ash contained up to 90 % $SiO_{2}$, indicating that it could be a valuable catalyst material. Pyrolysis of tyre waste over the catalyst reduced the oxygen content in the oil and yield. The oil yields of tyre pyrolysis without a catalyst and over zeolite Y were 38 wt% and 35 wt%, respectively. The main components identified in the tyre pyrolysis gas were methane (27.6%), ethene (28.8%), and hydrogen (15.6%). The gas from catalytic pyrolysis was richer in CO and $CO_{2}$.