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EN
Three activated chars obtained from end-of-life tyre pyrolysis differing in activation time (AC110 – 110 min, AC130 – 130 min, and AC150 – 150 min) were successfully used as adsorbents for the removal of model dye – Rhodamine B (RhB) from aqueous solutions. The effects of solution pH, adsorption kinetics, and equilibrium adsorption were investigated. The results showed that the adsorption was strongly pH-dependent; the highest percentage of RhB dye adsorbed was obtained at pH 2.0 and the removal efficiency decreased with an increase in solution pH. Adsorption kinetics was analyzed using pseudo-first-order, pseudo-second-order, Weber-Morris, and Boyd kinetic models. It was found that the pseudo-second-order kinetic equation was the most appropriate for describing the adsorption kinetics and that the RhB adsorption process was controlled by a film diffusion mechanism. Adsorption equilibrium data were fitted to the Langmuir, Freundlich, Temkin, and Elovich isotherm models. The equilibrium data were best represented by the Langmuir model with the monolayer adsorption capacities of 69.96, 94.34, and 133.3 μmol/g for AC110, AC130, and AC150, respectively. It was concluded that the adsorption of RhB was closely correlated with the specific surface area (and activation time) of the activated chars.
PL
Recykling materiałowy zużytych opon samochodowych nabiera coraz większego znaczenia, stanowiąc przyjazną dla środowiska alternatywę dla powszechnie stosowanego odzysku energetycznego. W artykule omówiono bieżące trendy w technologiach rozdrabniania opon oraz przedstawiono sposoby kontroli jakości granulatów gumowych uzyskiwanych w wyniku mechanicznego rozdrabniania zużytych opon samochodowych, a także produktów ich modyfikacji. Ponadto w pracy przedstawiono możliwości standaryzacji oraz dalszego rozwoju procedur związanych z charakterystyką granulatów gumowych i regeneratów gumowych, co pozwoli na ich efektywniejsze wykorzystanie w przemyśle.
EN
Material recycling of waste tyres is gaining more and more attention as an environmentally friendly alternative to the commonly used energy recovery. This article discusses current trends in tyre shredding technologies and presents the methods of quality control of ground tyre rubber and products of its modification. Moreover, the paper presents the possibilities of standardization and further development of procedures related to the characteristics of ground rubber and reclaimed rubber, which will enable their more efficient industrial application.
PL
W artykule przedstawiono ocenę możliwości zastosowania karbonizatu ze zużytych opon samochodowych, jako zamiennika części koksiku w procesie spiekania rud żelaza. Przeprowadzono laboratoryjne próby spiekania, z udziałem do 20% mas. karbonizatu w sumie paliwa. Stwierdzono, że wraz ze wzrostem udziału karbonizatu w mieszance spiekalniczej pogarsza się wydajność procesu. Udział karbonizatu w mieszance spiekalniczej nie powinien przekraczać 10% mas.
EN
This article presents the assessment of the possibility to replace the part of coke breeze in the iron ore sintering process by chars from used tyres utilization. Laboratory sintering experiments were carried out, with up to 20 wt.% char in sintering mix. It was found that with the increase of the char proportion in the sinter mix, the productivity of sinter decreases. The share of char in the sinter mix should not exceed 10 wt.%.
EN
A mathematical model of waste tyre pyrolysis process is developed in this work. Tyre material decomposition based on a simplified reaction mechanism leads to main product lumps: noncondensable (gas), condensable (pyrolytic oil) and solid (char). The model takes into account kinetics of heat and mass transfer in the grain of the shredded rubber material as well as surrounding gas phase. The main reaction routes were modelled as the pseudo-first order reactions with a rate constant calculated from the Arrhenius type equation using literature values of activation energy determined for main tyre constituents based on TG/DTG measurements and tuned pre-exponential parameter values obtained by fitting theoretical predictions to the experimental results obtained in our laboratory reactor. The model was implemented within the CFD software (ANSYS Fluent). The results of numerical simulation of the pyrolysis process revealed non-uniformity of sample’s porosity and temperature. The simulation predictions were in satisfactory agreement with the experimentally measured mass loss of the tyre sample during pyrolysis process investigated in a laboratory reactor.
5
Content available Waste tires as a source of valuable chemicals
EN
The aim of the study was to determine the possibility of the isolation of valuable chemical compounds from pyrolysis oil obtained from the pyrolyzed waste car tires. Produced pyrolysis oil were subjected to a distillation process to isolate medium naphtha fraction average naphtha that contains limonene, which according to the literature data, can be used as an environmental friendly solvent in a number of cleaning agents. Considering the boiling point of limonene (176°C), the medium fraction of the separated oil was re-distilled to isolate compounds with temperature of boiling point between 174-177°C. The prepared sample was analysed by gas chromatography coupled with mass spectroscopy. Based on the chromatographic analysis, it was found that in a separate sample of pyrolysis oil the highest share constituted toluene, and then cyclobutane, benzene derivatives, which is essential in the chemical industry. The share of limonene was low (approx. 1%), what is explained by too high temperature of the pyrolytic process. The results of analysis and literature allow unequivocally state that in order to separate specific compounds from pyrolytic oil, parameters of this process should be first determined in pilot studies. In conclusion, it is believed that the pyrolysis of tires is suitable method of disposing of the waste, thereby obtaining products containing valuable compounds for the fuel and chemical industries.
PL
W pracy przeprowadzono badania doświadczalne pirolizy zużytych opon w zbudowanym do tego celu stanowisku pomiarowym. Wyniki badań pokazały wpływ temperatury na udziały poszczególnych frakcji produktu, stężenia kluczowych składników fazy ciekłej i gazowej oraz powierzchnię właściwą karbonizatów.
EN
In this work pyrolysis of waste tyres was investigated in the specially built experimental setup. The results show the effect of temperature on the yields of char, iol and gas obtained in the process. Also, the concentration of key species in gas and liquid phases and specific surface area of chars are presented.
7
Content available Analysis of Carbon Black from Tyres Pyrolysis
EN
The article presents the results of the analysis of the pyrolysis products (char) from waste tires. Pyrolysis was carried out in four temperature 450, 500, 550, 600°C. Yield of solid product (char) ranged from 37% for the temperature of 450°C to 43% for the temperature of 500°C. The SEM analysis of obtained samples shows that the surface properties (size) depends on the process temperature.
PL
W artykule przedstawiono wyniki analizy produktów pirolizy opon samochodowych. Piroliza była prowadzona w temperaturach 450, 500, 550, 600°C. Wychód karbonizatu (produktu stałego pirolizy) wynosi od 37% dla temperatury 450°C do 43% dla temperatury 500°C. Przedstawiono wyniki analizy SEM, które wskazują, że wielkość powierzcni karbonizatu zalezy od temperatury procesu.
EN
Civil engineering and mainly geotechnics and pavement engineering are the possible domains of application for the end of life tyres. They are used in geotechnical applications as backfill or lightweight fill material in substitution or in combination with natural soils. The mechanical behaviour of tyre chip-sand mixtures was studied in a series of CD triaxial tests. The study was focused on random distribution of tyre chips within the mixture. Initial modulus of deformation, angle of internal friction and cohesion were evaluated for each series of test. A composite conserves a good shear resistance at large strains. The mode of failure depends on the tyre content. The internal shear mechanism and the reinforcement mechanism of the composite are discussed as a function of tyre content, chips orientation and stress level.
9
Content available remote Badania aktywacji parą wodną karbonizatów ze zużytych opon samochodowych
PL
Zaprezentowano aktualne osiągnięcia w zakresie wykorzystania procesu pirolizy zużytych opon samochodowych do otrzymywania prekursorów adsorbentów węglowych. Przedstawiono wyniki badań procesu aktywacji parą wodną karbonizatów z opon samochodowych. Surowiec do badań pochodził z Polski i Wielkiej Brytanii. Karbonizaty otrzymano w procesie pirolizy opon prowadzonej w złożu stałym oraz w piecu obrotowym. Zaobserwowano, że karbonizaty z opon, niezależnie od pochodzenia oraz warunków wstępnej obróbki pirolitycznej (retorta czy piec obrotowy), wykazują podobne zachowanie w procesie aktywacji. Wraz z wydłużeniem czasu aktywacji maleje uzysk produktu oraz rośnie w nim zawartość popiołu ze względu na zachodzące reakcje zgazowania. W wyniku procesu aktywacji uzyskano adsorbenty o dobrych parametrach jakościowych. Ponad 2-krotnie wzrosła pojemność sorpcyjna wobec jodu oraz powierzchnia właściwa. Przedstawiono korelacje właściwości adsorpcyjnych produktów aktywacji z czasem procesu oraz wytyczne do prowadzenia procesu aktywacji karbonizatów ze zużytych opon w piecu obrotowym w skali przemysłowej. Właściwości adsorpcyjne produktu wykazują maksimum przy około 50 minutach trwania procesu aktywacji parą wodną.
EN
The current state of waste tyres utilization by pyrolysis to obtain carbonaceous adsorbents' precursors has been presented. At present, the great number of works concerning this subject are realized. The test results of the waste tyres' chars steam activation have been shown. Feedstock for experiments origined from Poland and Great Britain. The chars were received from the pyrolysis process of tyres, which have been performed in the retort (fixed bed) and rotary kiln. Temperature of the pyrolytic pretreatment was about 500°C for rotary kiln and 600°C in the case of retort. Activation process has been carried out at temperature 850°C. Time of processing has been changed in the range of 15 ÷ 20 minutes. The chars from waste tyres have similar behaviour during the process of steam activation apart from their origin and conditions of the pyrolytic pretreatment. Prolongation of steam activation time results in the decreasing of product yield and increasing of ash contents according to reaction of gasification. The adsorbents obtained during the waste tyres chars steam activation have good qualitative parameters. Iodine number and specific surface area of activated char grew up twice compared to pyrolytic char (570 mg/g and 480 m²/g respectively). The correlations of adsorptional properties with time of processing and the guidelines for the chars activation in rotary kiln in industrial scale have been presented. The best product showed maximum of the adsorptional properties for about 50 minutes of the steam activation.
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