|
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.
Fulltext: content.csg - PDF Plný tet: SKMBT_C22012102413551 - PDF
|
|
Hydrodynamic and Heat Transfer Model of a Gas-Liquid Microreactor
Křišťál, Jiří ; Stavárek, Petr ; Staněk, Vladimír ; Jiřičný, Vladimír ; Simoncelli, A. ; Vanhoutte, D. ; Tarchini, R. ; Talford, M. ; Hass-Santo, K. ; Benzinger, W.
In this contribution we present a hydrodynamic and heat transfer model of a microreactor for a gas-liquid reaction. In the course of formulation of the model, we considered the characteristic features of the studied system – the gas-liquid flow pattern and the change in physical properties induced by pressure and temperature variation along the microreactor. Based on the input information (gas and liquid flow rates, compositions, temperatures), the model calculates the two-phase pressure drop and outlet temperature as the principal result. These results serve as a basis for the design of an intensified pilot scale microreactor.
Fulltext: content.csg - PDF Plný tet: SKMBT_C22012102413550 - PDF
|
|
BIORAF – Biorefinery Research Centre of Competence
Topka, Pavel ; Hajšlová, J. ; Demnerová, K. ; Cepák, Vladislav ; Vosátka, Miroslav ; Jiřičný, Vladimír ; Jandejsek, Z. ; Kopenec, J. ; Šmejkal, M. ; Kaštánek, P. ; Šolcová, Olga
The project, which started in 2012, creates an interdisciplinary center with high innovation potential for sustainable utilization of renewable sources, and will bring the Czech Republic to the leading position in next-generation biorefinery within next eight years. The project links the private sector with experts from different fields of science (e.g., biosciences, phycology, analytical chemistry, enzymology, microbiology, chemical and biochemical engineering, material engineering, etc.).
Fulltext: content.csg - PDF Plný tet: SKMBT_C22012102413542 - PDF
|
|
Activity of CoMo/MSA Catalysts in Benzothiophene Hydrodesulfurization, Cumene Cracking and Cyclohexene Isomerization
Gulková, Daniela ; Kaluža, Luděk ; Zdražil, Miroslav ; Vít, Zdeněk
It was found that MoO3 does not adsorb onto pure SiO2 despite its relatively high surface area (400 m2/g). In contrast, SA52, MSA30, and MSA19 with surface areas 430, 580 and 600 m2/g adsorbed about 14, 7 and 3 wt. % of MoO3, respectively. The content of Al2O3 in the SA based materials thus well correlated with the adsorption loadings of MoO3 achieved by the saturation experiments. Moreover, it was acquired that the highest dispersion and HDS activities were achieved over catalysts containing dealuminated MSA supports despite of relatively low loadings of Mo. After Co deposition, the weight normalized activities in BT HDS increased 2.2 and 4.3 times on effective MoS2 promotion by Co on more acidic supports. Furthermore, those catalysts keep the high acidities of the original supports, as it was determined by cyclohexene isomerization and cumene cracking, while industrial reference CoMo catalysts supported onto gamma-Al2O3 was found to exhibit low acidity.
Fulltext: content.csg - PDF Plný tet: SKMBT_C22012102413541 - PDF
|
| |
| |
| |
| |
|
Gas-Liquid Flows in Thin-Gap Electrochemical Microchannels – PIV Study
Záloha, Petr ; Křišťál, Jiří ; Jiřičný, Vladimír ; Aubin, J.
We focused on the study of the local hydrodynamics of liquid in gas-liquid flow in thingap microchannels (width 10 mm, depth 2 mm - 0.1 mm). Two-phase flow was obtained by injecting bubbles into the channel to mimic the gas generation during electrochemical reactions. The liquid flow velocity vectors were obtained by the PIV technique. Single phase measurements were used to verify our method by comparison with the theoretical velocity profiles. Local velocity fields around single bubble were evaluated.
Fulltext: content.csg - PDF Plný tet: SKMBT_C22012102413481 - PDF
|
| |