mass transfer coefficient

The kinetics granules of boric acid (GBA) dissolution were investigated based on the solution temperature and stirring frequency. Experimental mass transfer coefficients were determined and compared with theoretical values. The results indicate that increasing the stirring frequency and the solvent temperature increases the mass transfer coefficient. A computational relationship was derived, enabling the prediction of GBA dissolution based on solution temperature and stirring frequency.

Since slag and coal fly ash (CFA) are major global pollutants produced by thermal power plants (TPPs), special attention should be paid to their rational disposal. Scanning electron microscopy (SEM) was used to study the morphology of CFA and it was suggested that the use potential of CFA is high due to the presence of a large number of cenospheres (CSs), that can be recovered mostly by wet methods for the production of the wide range of products with improved properties.

The extraction of the solid component from the rectilinear capillary has been investigated. The presence of two extraction zones (convective and molecular diffusion) was confirmed. The effect of the system vacuumizing on the extraction rate has been studied. The convection zone during vacuumizing was found to be increased due to the appearance of the vapor phase bubbles. The mass transfer coefficients for the convective zone have been determined.

The dissolution process of potassium chloride particles in the apparatus with two-blade mechanical stirrer was investigated and the mass transfer coefficient was determined. The experimental results were generalized by criterion dependence. The independence of the mass transfer coefficient from the solid particles diameter was confirmed. A countercurrent process of potassium salt dissolution in two apparatuses with a mechanical stirring was considered. A mathematical model for countercurrent dissolution was developed and the efficiency of this process was determined.

The structure of an emulsion formed in wastewater from edible oils production has been investigated. The type of emulsifier has been determined and the method of emulsion destruction has been proposed, providing further quality treatment of wastewater via liquid-extraction method. The resulting equilibrium and operating lines of the process were received. The number of transfer stages has been determined. The mathematical model of liquid-extraction wastewater treatment was built.

Kinetics of flavonoids extraction from hops strobiles extraction cake is investigated, total value of mass-transfer resistance is determinate, taking into consideration anatomic features of plant raw material, especially cellular and intercellular environment existence. Validity of proposed mathematical tools technique for evaluation of main kinetic constant of process is confirmed. Obtained result can be applied for equipment calculation in the design of process flow charts of cellular structure solid bodies.

The dissolution kinetics of potassium sulfate dissolved in water under pneumatic mixing has been investigated. The mass transfer coefficients were determined by the experiments, as well as on the basis of the local isotropic turbulence theory. The ratio between theoretical and experimental data was found to be satisfying that allows to determine the theoretical mass transfer coefficient to calculate the mentioned process.

The adsorption of cephalexin (CFX) onto walnut shell-based activated carbon (AC) was investigated. The mass transfer coefficients were calculated by employing constant wave propagation theory. The effect of different conditions on the mass transfer coefficient was also studied. In addition, three models to predict the mass transfer coefficient were developed.

The carbon dioxide absorption by unicellular microalgae has been studied. The stages of the process have been examined taking into account the peculiarities of cultivation conditions, in particular the presence of cellular and intercellular environment. The constants realizing the mathematical model of carbon dioxide absorption from the air by microalgae cells have been determined. The obtained results allow to predict the absorption kinetics and develop the equipment for gas wastes cleaning while implementation of the industrial process.