Search results for "Liquid solid"
showing 4 items of 4 documents
Photocatalytic and Catalytic Reactions in Gas–Solid and in Liquid–Solid Systems
2019
Abstract Heterogeneous photocatalytic and thermal-catalytic reactions are here presented focusing the differences and similarities between the two processes. When possible, the comparison was made for the same chemical reaction in the presence of an inorganic material playing the role of both catalyst or/and photocatalyst. Several examples are presented where a catalytic reaction can occur at milder experimental conditions and, particularly, at lower temperature when the system is also irradiated by UV and/or visible light. The differences in mechanistic aspects, conversions, and selectivities between catalytic and photocatalytic reactions will be also considered because these occurrences a…
Gas-liquid-solid Operation of a High Aspect Ratio Self-ingesting Reactor
2012
Gas-liquid stirred vessels are widely employed to carry out chemical reactions involving a gas reagent and a liquid phase. The usual way for introducing the gas stream into the liquid phase is through suitable distributors placed below the impeller. An interesting alternative is that of using “self ingesting” vessels where the headspace gas phase is injected and dispersed into the vessel through suitable surface vortices. In this work the performance of a Long Draft Tube Self-ingesting Reactor (LDTSR) dealing with three-phase (gas-liquid-solid) systems, is investigated. Preliminary experimental results on the effectiveness of this contactor for particle suspension and gas-liquid mass transf…
Liquid–solid interfaces: structure and dynamics from spectroscopy and simulations
2014
Liquid–solid interfaces play an important role in a number of phenomena encountered in biological, chemical and physical processes. Surface-induced changes of the material properties are not only important for the solid support but also for the liquid itself. In particular, it is now well established that water at the interface is substantially different from bulk water, even in the proximity of apparently inert surfaces such as a simple metal. The complex chemistry at liquid–solid interfaces is typically fundamental to heterogeneous catalysis and electrochemistry, and has become especially topical in connection with the search for new materials for energy production. A quite remarkable exa…
Unsuspended mass of solid particles in stirred tanks
1998
On propose une technique originale pour la determination de la fraction de particules solides non suspendues a des vitesses d'agitation inferieures a N js . La technique repose sur le concept des systemes jumeles et est completee par une technique de tracage et de detection pour la phase solide. Les resultats obtenus avec un reservoir chicane agite par une turbine Rushton, montrent que la fraction de solides ne quittant jamais le fond du reservoir peut etre simplement correlee au rapport entre la vitesse d'agitation et la vitesse de suspension complete de Zwietering. On montre qu'a des vitesses de l'agitateur d'environ 80% de la vitesse de suspension complete de Zwietering, pratiquement tou…