25 research outputs found

    Pyrolysis procesing of waste peanuts crisps

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    Wastes are the most frequent "by-product" of human society. The Czech Republic still has a considerable room for energy reduction and material intensiveness of production in connection with the application of scientific and technical expertise in the context of innovation cycles. Pyrolysis waste treatment is a promising alternative to the production of renewable hydrogen as a clean fuel. It can also reduce the environmental burden and the amount of waste in the environment at the same time. This paper presents the laboratory pyrolysis experiments of peanuts crisps waste to the final temperature of 800 °C. After the pyrolysis process of the selected waste a mass balance of the resulting products, off-line analysis of the pyrolysis gas and evaluation of solid residue in terms of adsorption properties and energy production and liquid products were carried out. The highest concentration of measured hydrogen (66 vol. %) was analysed during the 4th gas sampling at the temperature varying from 750 to 800 °C

    Vliv chemické aktivace na sorpční charakteristiky uhlíkatých materiálů

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    Two samples of hardwood, beech and a mixture of beech and oak were pyrolyzed by continuous chemical activation with K2CO3. Two final temperatures were tested on activated samples (550 °C, 750 °C). In the same temperature regime, also non-activated original samples were pyrolyzed. The sorption for carbonaceous material was measured with a high-pressure thermal analyzer (TGA-HP50) in the presence of nitrogen and the carbon dioxide atmosphere in the range of pressure from 0,03 to 4,5 MPa, respectively from 0,03 to 2 MPa. The sorption experiments were carried out at three different temperatures – 20, 30 a 40 °C. The tests indicate that the final temperature of activation and sorption conditions (pressure, temperature) have significant impact on sorption properties of material.Dva vzorky tvrdého dřeva, buk a směs buk/dub, byly pyrolyzovány se současnou chemickou aktivací K2CO3. Testovány byly dvě konečné teploty pyrolýzy pro aktivaci vzorků (550 °C, 750 °C). Ve stejném teplotním režimu byly pyrolyzovány i neaktivované původní vzorky. Sorpce na uhlíkové materiály byly měřeny na vysokotlakém termickém analyzátoru (TGA-HP50) v atmosféře dusíku a oxidu uhličitého v rozmezí tlaků od 0,03 do 4,5 MPa, respektive od 0,03 do 2 MPa. Sorpční experimenty probíhaly při třech teplotách – 20, 30 a 40 °C. Ukazuje se, že konečná teplota aktivace a sorpční podmínky (tlak, teplota), mají významný vliv na sorpční vlastnosti materiálu

    Application of pyrolysis process in processing of mixed food wastes

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    The food industry produces large amounts of solid and also liquid wastes. Different waste materials and their mixtures were pyrolysed in the laboratory pyrolysis unit to a final temperature of 800°C with a 10 minute delay at the final temperature. After the pyrolysis process of the selected wastes a mass balance of the resulting products, off-line analysis of the pyrolysis gas and evaluation of solid and liquid products were carried out. The highest concentration of methane, hydrogen and carbon monoxide were analyzed during the 4th gas sampling at a temperature of approx. 720–780°C. The concentration of hydrogen was measured in the range from 22 to 40 vol.%. The resulting iodine numbers of samples CHFO, DS, DSFW reach values that indicate the possibility of using them to produce the so-called “disposable sorbents” in wastewater treatment. The WC condensate can be directed to further processing and upgrading for energy use.Web of Science181231

    Characterization of tar deposits, extraction and sorption properties

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    The main goal of this paper was to characterize and find a useful solution for the decomposition of tar deposits. For the experimental part, tar deposits, formed by polymerization and condensation reactions, were chosen from a storage tank for tars. At first the initial analyses of tar deposits (elemental, thermogravimetric, and calorimetric analyses) were performed. After the characterization, the tar deposits were extracted in the Soxhlet extractor by acetone, toluene, and quinolone and activated with potassium hydroxide. As the final step of this work, the sorption characterization on the 3Flex Surface Characterization Analyzer (Micromeritics) was performed. The specific surface area of the samples was evaluated using two methods – a single point measurement at p/p0=0.2 and BET method. Micropore and external surface areas were calculated based on a t-plot analysis (carbon black model)

    Surface plasmon resonance imaging sensor for detection of photolytically and photocatalytically degraded glyphosate

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    Glyphosate is one of the most widely used pesticides, which, together with its primary metabolite aminomethylphosphonic acid, remains present in the environment. Many technologies have been developed to reduce glyphosate amounts in water. Among them, heterogeneous photocatalysis with titanium dioxide as a commonly used photocatalyst achieves high removal efficiency. Nevertheless, glyphosate is often converted to organic intermediates during its degradation. The detection of degraded glyphosate and emerging products is, therefore, an important element of research in terms of disposal methods. Attention is being paid to new sensors enabling the fast detection of glyphosate and its degradation products, which would allow the monitoring of its removal process in real time. The surface plasmon resonance imaging (SPRi) method is a promising technique for sensing emerging pollutants in water. The aim of this work was to design, create, and test an SPRi biosensor suitable for the detection of glyphosate during photolytic and photocatalytic experiments focused on its degradation. Cytochrome P450 and TiO2 were selected as the detection molecules. We developed a sensor for the detection of the target molecules with a low molecular weight for monitoring the process of glyphosate degradation, which could be applied in a flow-through arrangement and thus detect changes taking place in real-time. We believe that SPRi sensing could be widely used in the study of xenobiotic removal from surface water or wastewater.Web of Science2223art. no. 921

    Chování plynů při chlazení konvertorových trysek

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    Import 20/04/2006Prezenční výpůjčkaVŠB - Technická univerzita Ostrava. Fakulta metalurgie a materiálového inženýrství. Katedra (617) chemi

    Effect Of Chemical Activation On Sorption Characteristics Of Selected Wood Samples / Vliv Chemické Aktivace Na Sorpční Charakteristiky Uhlíkatých Materiálů

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    Dva vzorky tvrdého dřeva, buk a směs buk/dub, byly pyrolyzovány se současnou chemickou aktivací K2CO3. Testovány byly dvě konečné teploty pyrolýzy pro aktivaci vzorků (550 °C, 750 °C). Ve stejném teplotním režimu byly pyrolyzovány i neaktivované původní vzorky. Sorpce na uhlíkové materiály byly měřeny na vysokotlakém termickém analyzátoru (TGA-HP50) v atmosféře dusíku a oxidu uhličitého v rozmezí tlaků od 0,03 do 4,5 MPa, respektive od 0,03 do 2 MPa. Sorpční experimenty probíhaly při třech teplotách - 20, 30 a 40 °C. Ukazuje se, že konečná teplota aktivace a sorpční podmínky (tlak, teplota), mají významný vliv na sorpční vlastnosti materiál

    Reynoutria japonica, an invasive herb as a source of activated carbon for the removal of xenobiotics from water

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    Japanese knotweed (JK) is considered one of the most problematic invasive plants. Great attention was paid to research any possibilities of reducing its occurrence. This work deals with possibilities of easy transformation of JK into carbon adsorbent (AC), which is usable for sorption of diclofenac and paracetamol. Activated carbons were prepared by microwave heating using H3PO4, NaOH and sodium methanolate as the chemical agents. Characterization of AC's was carried out using BET, ATR-FTIR, SEM, adsorption equilibrium and kinetics experiments. The pseudo-second-order model showed the best similarity criteria for all studied systems adsorbent/adsorbate. The sorption efficiency was influenced by the choice of activating agent, where the ox-ox interactions between the planes of the obtained adsorbent and the aromatic rings of adsorbate and the interactions between the adsorbate and AC functional groups of the surface played an important role. AC-H3PO4 exhibited highest adsorption capacity for both diclofenac (87.09 mg.g(-1)) and paracetamol (136.61 mg.g(-1)).Web of Science309art. no. 12331

    Determination of specific surface of activated mesocarbons by sorption of organic vapors

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    The determination of specific surface of activated mesocarbons prepared from coal tar pitch by sorption of organic vapors and the operating factors affecting their performances were investigated. Proposed paper deals with alternative experimental method based on weight registration during adsorption of pure vapors of volatile organic compounds VOCs on tested samples. Thermogravimeter TGA-HP50 was used for sorption experiments where activated mesocarbon microbeads were the sorbent and vapors of benzene, toluene, acetone and cyclohexane were used as adsorbate. Primary data were actual weight of the tested sorbent and absolute pressure of organic vapor. Experimental data were fitted by Langmuir model of adsorption isotherm. Specific surface was determined from evaluated parameters. Obtained results were compared with results from standard nitrogen S-BET method. Specific surfaces evaluated from both methods are comparable. The influence of important parameters such as chemical activation, extraction and addition of catalytic agents on activated mesocarbons was studied too. Coal tar pitch as raw material was thermally treated together with Lewis acid (FeCl3). Final solid sorbents were prepared by chemical activation of pyridine-insoluble (PI) matters using potassium hydroxide. Weight ratio of activated agent (potassium hydroxide) to PI matters was 1:5, and temperature of activation was 850 °C. It was found that three samples which were activated had greater specific surface area than the one (B) that was not activated, also as they are appropriate for adsorbing the selected adsorptives.Web of Science121143642
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