Effective methodologies for efficient preparation of semicarbazones from aldehydes or ketones via milling and the subsequent regeneration of the parent carbonyls by gaseous nitrogen dioxide are described under solid-solid and gas-solid reaction conditions, respectively. These methods are fast, simple and environmentally benign which do not require the use of any auxiliaries such as catalyst...

In physical adsorption the interaction of adsorbed molecules with solids is mainly due to induction forces acting between the surface electric field and permanent or induced dipoles in the adsorbate, and to L O N D O N dispersion forces, these prevailing, for example, in adsorption of apolar molecules In the last years it has been shown that the dielectric behaviour of the heterogeneous adsorbe...

The main advantage of a fluidized bed is its capability in excellent gas-fuel mixing. However, due to the lacks of gas radial momentum, its lateral mixing of gas-solid is not adequate. Therefore, this research is focused on fluidized bed hydrodynamics enhancement using the modified gas distributor plate design. For getting an optimum fluidized bed hydrodynamics prediction, three different class...

The local solid flow structure of gas-solid bubbling fluidized bed was investigated to identify and characterize the particle clusters. Extensive mathematical calculations were carried out using the energy-minimization multi-scale (EMMS) approach for evaluating cluster properties including the velocity, the size and the void fraction of clusters in the dense phase of the bed. The results showed...

INTRODUCTION To account for meso-scale phenomena in coarse grid simulations, Reynolds stress terms appearing in the filtered gas-solid flow equations have to be modeled. Filtered models for the gas-solid momentum transfer are focused on and possible approaches are discussed. Three-dimensional steady-state simulations of developing flow in the bottom section of a riser in which the solid phase i...

This work investigates the effect of different conditions of PFO thermal cracking from two PFO samples on liquid, solid and gas product yield and asphaltene removal efficiency in a new designed experimental setup. No need to use a catalyst, simple operating system and experiment conditions, the ability to use water as a cheap carrier gas and high asphaltene extraction efficiency without the use...

Effect of scale on the hydrodynamics of gas-solid fluidized beds was investigated in two fluidized beds of 152 mm and 78 mm in diameter.  Air at room temperature was used as the fluidizing gas in the bed of sand particles. The Radioactive Particle Tracking (RPT) technique was employed to obtain the instantaneous positions of the particles at every 20 ms of the experiments. These data were u...

effect of scale on the hydrodynamics of gas-solid fluidized beds was investigated in two fluidized beds of 152 mm and 78 mm in diameter.  air at room temperature was used as the fluidizing gas in the bed of sand particles. the radioactive particle tracking (rpt) technique was employed to obtain the instantaneous positions of the particles at every 20 ms of the experiments. these data were used ...