National Repository of Grey Literature 34 records found  beginprevious25 - 34  jump to record: Search took 0.01 seconds. 
Concentration of HCl, HF and Sulfur Compounds in Fuel Gas from Fluidized Bed Gasification of Coals and Wood by Steam-Oxygen Mixtures
Svoboda, Karel ; Pohořelý, Michael ; Jeremiáš, Michal ; Kameníková, Petra ; Skoblia, S. ; Beňo, Z. ; Šyc, Michal
We have concentrated in our study on FB gasification of two kinds of coals differing in reactivity, ash content and composition and hard wood at temperature 850 oC. Our attention was particularly devoted to speciation of sulfur compounds, presence of HCl, HF and tar compounds in fuel gas. Silica sand and mixture of silica sand with gradually added dolomite was used as basic particulate bed material in FB gasification. The results have shown that presence of dolomite particles in the fluidized bed and presence of dolomite dust reduces concentrations of all sulfur species, but the reduction of thiophene concentration is more pronounced. Presence of dolomite in FB causes substantial decrease of HCl concentration and moderate decrease of HF concentration in fuel gas. Accumulation of char and ash with active calcium based components leads to moderate reduction of HCl and sulfur compounds concentration in fuel gas.
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Fluidized Bed Gasification of a Sub-Bituminous Coal, Biomass and Coal-Biomass Co-Gasification by a Gas Containing Oxygen-CO2 Mixtures
Svoboda, Karel ; Pohořelý, Michael ; Jeremiáš, Michal ; Kameníková, Petra ; Skoblia, Sergej ; Šyc, Michal ; Punčochář, Miroslav
Based on the above stated facts we concentrated in our study on FB gasification with higher concentrations of CO2 in gasification medium and on gasification of a reactive subbituminous German coal, biomass (wood) and a coal-biomass blend at temperatures between 800 oC and 900 oC. Out attention was particularly devoted to effects of CO2 concentrations and gasification temperature on producer gas heating value, energy yield, tar and BTX yields in comparison with FB gasification with steam-O2 mixtures.
Fluidized Bed Gasification of Flax used for Phytoextration of Heavy Metals
Pohořelý, Michael ; Šyc, Michal ; Jeremiáš, Michal ; Vosecký, Martin ; Kameníková, Petra ; Skoblia, Sergej ; Svoboda, Karel ; Punčochář, Miroslav
This study was aimed at determination of distribution of heavy metals among producer gas and individual size fractions of ash matter, i. e. bed ash and cyclone ash, formed in fluidized bed steam biomass gasification. Knowledge of distribution of heavy metals is necessary for further utilization of all products of the gasification.
Vliv přídavku oxidu uhličitého ke zplyňovacímu médiu při atmosférickém zplyňování vodní parou ve fluidním loži křemenného písku a vápence
Jeremiáš, Michal ; Pohořelý, Michael ; Vosecký, Martin ; Skoblia, Sergej ; Kameníková, Petra ; Svoboda, Karel ; Punčochář, Miroslav
The aim of this project was to evaluate the effect of addition of CO2 to the gasification agent during allothermal steam fluidized bed gasification of biomass at constant temperature about 800 °C. Moreover, the effect of different fluidized bed materials such as silica sand and limestone together with the effect of temperature on producer gas composition was also examined. Experiments led to conclusions that CO2 added to the gasification agent was converted to CO to only very limited extent while CO2 dilution effect was relatively strong. The CO2 to CO conversion was exhanced by the use of limestone as the bed material. Limestone showed also strong catalytic activity towards reduction in tar content in the producer gas and higher production of H2, CO2 and CO in comparison with silica sand. Optimal temperature for in the bed-use of limestone in the gasification process was proposed to be around 850 °c under the given experimental conditions.
Vedlejší (nežádoucí) úniky plynu a cirkulace částic písku a koksíku v duálním systému s fluidní vrstvou a pneumatickým transportem – vliv návrhových parametrů a provozních podmínek
Svoboda, Karel ; Kalisz, S. ; Martinec, J. ; Pohořelý, Michael
Our study has been concentrated on influence of geometric parameters (height of cylindrical chamber for pneumatic transport (PT), flat perforated sheet and conical gas distributor, different upper part for return of solids, total orifice cross sectional area) and operating parameters (gas flow rate in PT-column, height of fluidized bed) on circulating flow of solids. In a limited extend gas leakage study on a dual fluidized bed (FB)-PT system for circulation of solids has been performed.
Experimentální sledování bublin stoupajících v linii
Stanovský, Petr ; Zedníková, Mária ; Růžička, Marek ; Drahoš, Jiří ; Sanada, T. ; Shirota, M. ; Sato, A. ; Watanabe, A.
Present contribution addresses some aspects of the behavior of a bubble chain composed of bubbles with Re in the range (based on the terminal velocity of single bubble). Bubble chains were created using bubble generator with oscillating needle or acoustic bubble generator. These devices enable to create bubble chains with different initial spacing and bubble diameter. Air bubbles were rising in various liquids as ultrapure water, silicon oils and ethanol.
Detailed Composition of the Low-Calorific Producer Gas from the Fluid-Bed Gasification of Biomass.
Pohořelý, Michael ; Vosecký, Martin ; Skoblia, Sergej ; Kameníková, Petra ; Punčochář, Miroslav ; Vošta, J. ; Svoboda, Karel
The gaseous product from gasification (producer gas) can be effectively utilized in a variety of ways including power generation, production of chemicals, fuels for transport and substitution of natural gas for heating. The gasification technology, needed gas composition and cleaning, tolerable contents of impurities, toxic compounds and heating value of the producer gas are determined usually by the end user of the gas.
Theoretical Dependence of Temperature of Burning Coal and Wood Particles on Conditions of Fluidized bed combustion
Svoboda, Karel
The report brings presentation and solution of two theoretical models for estimation of temperature of burning particles of low-ash coals (smaller particles) and high ash coals with particles above 1 mm in fluidized bed combustion. The attention is focused mainly on effects of fluidized bed temperature, operating pressure and size of particles on difference between fluidized bed (bulk) and burning particle temperature.
Emise oxidů dusíku a chování těžkých kovů při atmosférickém fluidním spalování vysušeného čistírenského kalu
Pohořelý, Michael ; Svoboda, Karel ; Hartman, Miloslav ; Vošta, J.
It seems that increasing amount of heavy metals is transfered to fly ash under higher gas flow rates, as effect of particle attrition and entrainment from the FB. The experimental results suggest that for efficient combustion of dried sewage sludge in static or circulating fluidized bed the temperature should be higher than 850°C.

National Repository of Grey Literature : 34 records found   beginprevious25 - 34  jump to record:
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