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Basic characteristics of sulfide catalysts for the direct decomposition of H2S
Bonnet, Florian; Kaluža, Luděk
2024 - anglický
Sulfide catalysts are crucial in the hydrodesulfurization (HDS) of petroleum fractions, facilitating the hydrogenolysis of carbon-sulfur bonds. This process generates significant volumes of hydrogen sulfide (H2S), which is typically processed in the Claus unit. However, excess H2S can overwhelm the Claus process, creating both operational and environmental challenges. Researchers are now exploring sulfide catalysts for the direct thermo-catalytic decomposition of H2S to address this issue. Supported catalysts, like Mo/Al2O3, and commercial catalysts, considered typical monolayer-type well-dispersed catalysts, show the highest O2 uptake, ranging from 41.29 μmol/g for MoS2/Al2O3 (KLO) to 58.70 μmol/g for the commercial 715. Unsupported multilayer catalysts, such as Ni/MoWS2 (KKP), exhibit lower O2 uptake at 2.54 μmol/g, though it demonstrates high HDS activity with thiophene. Moreover, O2 uptake effectively describes the sintering of the Mo monolayer phase during the thermocatalytic reaction of H2S at 800°C. These O2 uptakes clearly correlate with the XRD patterns, where the MoS2 phase is X-ray amorphous with an O2 uptake of about 19.04 μmol/g, while the MoS2 phase in the spent catalyst shows certain crystallinity exhibiting an average particle size by Scherrer equation of about 6 nm and the O2 uptake of 1.63 μmol/g. O2 chemisorption thus serves as a valuable measure of the dispersion of Mo sulfides. The results obtain with the study of CoMo/Al2O3 (KJJ-family catalysts), highlight the correlation between the increasing amount of adsorbed O2 with the increasing nominal loading of MoO3 and the increasing rate constant of thiophene kTH. This research reveals the potential of these catalysts in hydrocarbon refining. The findings underline the connection between catalytic chemistry, process engineering, and environmental sustainability, with the objective to enhance industrial refining processes.
Klíčová slova:
sulfide catalyst; O2 chemisorption; H2S decomposition
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Basic characteristics of sulfide catalysts for the direct decomposition of H2S
Sulfide catalysts are crucial in the hydrodesulfurization (HDS) of petroleum fractions, facilitating the hydrogenolysis of carbon-sulfur bonds. This process generates significant volumes of hydrogen ...
Measurements on KR-D-11B Optimized Subsonic Blade Cascade
Šimurda, David; Hála, Jindřich
2023 - anglický
This report contains results and evaluation of aerodynamic measurements conducted on a subsonic compressor blade cascade.
Klíčová slova:
compressor blade cascade; experiment; subsonic flow; optimized profile
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Measurements on KR-D-11B Optimized Subsonic Blade Cascade
This report contains results and evaluation of aerodynamic measurements conducted on a subsonic compressor blade cascade.
2TDK Railway, profile P18. Datings. Final Report.
Bosák, Pavel; Zupan Hajna, N.; Hercman, H.; Horáček, I.; Kdýr, Šimon; Kogovšek, B.
2023 - anglický
Samples for datings were taken in the railway construction (2TDK) near village of Divača, Classical Karst on October 12, 2021: (1) vertebrate bones in cave 2TDK – 002 at the profile P18, cave entrance appeared during the construction operations on cleaned karst surface in a wall of karst depression. Samples of mammal bones and gastropods were collected in situ on cave bottom, and (2) pieces of speleothems occurring in non in situ position on artificially planated surface near the cave opening were collected. U-series: no numerical date was obtained as geochemistry of sample indicate open system, probably due to recrystallization of sample in soil cover. Paleomagnetism: The transition of N- and R-polarized samples cannot be identified more precisely as U-series radiometric dating yielded no numerical results. The transition easily can represent Brunhes/Matuyama boundary (at 773 ka) as well as any of older such transitions (e. g., base of Jaramillo, base of Olduvai). In any case the speleothem grew in a closed cave space with roof, probably as flowstone (inclusion of red soils above the base) and later as baldachin on eroded allogenic fill of the paleocave. Vertebrate paleontology: bone remains of small and larger vertebrates represent subrecent to Holocene species. Sorex alpinus represents the species quite rare in fossil record, but recetly limited to variegated woodland habitats with high surface humidity. A chamois Rupicapra rupicapra represents a resident species present in Slovenia throughout all stages of a glacial cycle, recently restricted to mountain habitats.
Klíčová slova:
Divača Karst; unroofed cave; speleothem; U-Th dating; paleomagnetism; zoopaleontology
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
2TDK Railway, profile P18. Datings. Final Report.
Samples for datings were taken in the railway construction (2TDK) near village of Divača, Classical Karst on October 12, 2021: (1) vertebrate bones in cave 2TDK – 002 at the profile P18, cave entrance ...
Optical and Pneumatic Measurements on TR-U-11 Cascade
Luxa, Martin; Hála, Jindřich; Šimurda, David
2023 - anglický
The report contains results and evaluation of conducted optical (interferometry and schlieren technique) and pneumatic measurements on the first variant of the new tip section, intended for turbine rotor blade.
Klíčová slova:
transonic flow; rotor turbine blade; tip section
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Optical and Pneumatic Measurements on TR-U-11 Cascade
The report contains results and evaluation of conducted optical (interferometry and schlieren technique) and pneumatic measurements on the first variant of the new tip section, intended for turbine ...
Kráľova Lehota. Paleomagnetic research. Report
Elbra, Tiiu; Schnabl, Petr; Aidona, E.; Kdýr, Šimon; Uçar, Hakan; Pruner, Petr; Benediková, L.
2023 - anglický
Klíčová slova:
Archeological artefact; paleomagnetic dating; rock magnetism
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Kráľova Lehota. Paleomagnetic research. Report
Implementation of a plasticity model with advanced kinematic hardening rule for additively manufactured materials
Marek, René; Parma, Slavomír; Gabriel, Dušan; Džugan, J.
2023 - anglický
This technical report summarizes particularly the modeling part of the project DP 04_01_NPO “Emission-free technologies for local energy sources replacement” including development of models to describe multi-material 3D printed structures. The work is done in cooperation between COMTES FHT, a.s., the Institute of Thermomechanics of the Czech Academy of Sciences, v.v.i. and PROINNO, a.s. The goal of the project is the development of material models describing the behavior of multi-material components deposited by the direct deposition method (DED) under multiaxial cyclic loading.\nIn the report, a plasticity model suitable for materials prepared by the additive manufacturing method is compiled and used. The model uses Hill's plasticity condition, an advanced multi-component kinematic hardening rule, and an isotropic hardening rule. The associated flow rule is chosen and the implementation assumes the theory of small deformations. All constitutive relationships are presented and discussed for the selected model, and the model is thus fully and unambiguously formulated. The model is analytically integrated for a special case of loading and a special choice of parameters of the plasticity condition, namely transverse isotropy. A discretization scheme for numerical integration and procedures for FE implementation of the model are presented. For the FE implementation, a formulation in the displacement field is assumed, specifically the FE solver Abaqus and the implementation of the model using the UMAT interface are targeted. Several examples of the model's response to monotonic, uniaxial and biaxial cyclic loading trajectories are presented. \n Tato zpráva shrnuje postup prací na dílčím projektu DP 04_01_NPO “Emission-free technologies for local energy sources replacement” zahrnující vývoj modelů pro popis chování multi-materiálových 3D tištěných struktur řešený v konsorciu COMTES FHT, a.s., Ústav termomechaniky AV ČR, v.v.i. a PROINNO, a.s. Cílem projektu je vývoj materiálových modelů popisujících chování multi-materiálových komponent deponovaných metodou přímé depozice (DED) pří víceosém cyklickém zatěžování. \nVe zprávě je sestaven a použit model plasticity vhodný pro materiály připravené metodou aditivní výroby. Model využívá Hillovu podmínku plasticity, pokročilý vícesložkový model kinematického zpevnění a model isotropního zpevnění. Je zvolen asociovaný zákon tečení a implementace předpokládá teorii malých deformací. Pro zvolený model jsou uvedeny a diskutovány všechny konstitutivní vztahy a model je tak plně a jednoznačně formulován. Model je analyticky integrován pro speciální případ zatěžování a speciální volbu parametrů podmínky plasticity, konkrétně příčnou isotropii. Je prezentováno diskretizační schema pro numerickou integraci a procedury pro MKP implementaci modelu. U MKP implementace se předpokládá formulace v poli posunutí, konkrétně je pak cíleno na MKP řešič Abaqus a implementaci modelu pomocí rozhraní UMAT. Je prezentováno několik příkladů odezvy modelu na monotónní, jednoosé a víceosé cycklické zatěžovací trajektorie.\n
Klíčová slova:
plasticity; anisotropy; additive manufacturing
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Implementation of a plasticity model with advanced kinematic hardening rule for additively manufactured materials
This technical report summarizes particularly the modeling part of the project DP 04_01_NPO “Emission-free technologies for local energy sources replacement” including development of models to ...
Novel embedding resins for 3D-SEM II
Šlouf, Miroslav; Pavlova, Ewa; Strachota, Beata; Strachota, Adam; Nebesářová, Jana; Týč, Jiří; Krzyžánek, Vladislav; Skoupý, Radim
2023 - anglický
Research report for Thermo Fisher Scientific s. r. o., based on common project awarded by TA CR (program: National center of competence, TN01000008).
Klíčová slova:
novel embedding resins; 3D-SEM microscopy; higher e-beam resistance
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Novel embedding resins for 3D-SEM II
Research report for Thermo Fisher Scientific s. r. o., based on common project awarded by TA CR (program: National center of competence, TN01000008).
Aerodynamic Measurements on Subsonic Compressor Blade Cascades KR-D-7 and KR-D-8
Šimurda, David; Hála, Jindřich; Luxa, Martin; Radnic, Tomáš
2023 - anglický
This report contains results and evaluation of aerodynamic measurements conducted on two variant subsonic compressor blade cascades with MCA profile (KR-D-7) and DCA profile (KR-D-8) at transonic flow regimes.
Klíčová slova:
compressor blade cascade; experiment; transonic flow; subsonic flow; MCA profile; DCA profile
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Aerodynamic Measurements on Subsonic Compressor Blade Cascades KR-D-7 and KR-D-8
This report contains results and evaluation of aerodynamic measurements conducted on two variant subsonic compressor blade cascades with MCA profile (KR-D-7) and DCA profile (KR-D-8) at transonic flow ...
Aerodynamic Measurements on Transonic Compressor Blade Cascades KR-D-9 and KR-D-10
Šimurda, David; Hála, Jindřich; Luxa, Martin
2023 - anglický
This report contains results and evaluation of aerodynamic measurements conducted on two variant transonic compressor blade cascades with MCA profile (KR-D-10) and DCA profile (KR-D-9) at transonic flow regimes.
Klíčová slova:
compressor blade cascade; experiment; transonic flow; MCA profile; DCA profile
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Aerodynamic Measurements on Transonic Compressor Blade Cascades KR-D-9 and KR-D-10
This report contains results and evaluation of aerodynamic measurements conducted on two variant transonic compressor blade cascades with MCA profile (KR-D-10) and DCA profile (KR-D-9) at transonic ...
Jánovce. Paleomagnetic research. Report
Elbra, Tiiu; Kdýr, Šimon; Uçar, Hakan; Pruner, Petr; Schnabl, Petr
2023 - anglický
Klíčová slova:
Jánovce archeological site; Paleomagnetism; Rock magnetism
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Jánovce. Paleomagnetic research. Report
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