Diffusional limitations in liquid-phase reactions catalyzed by enzymes immobilized on porous supports: sucrose inversion by β-fructooxidase immobilized on IRA-93 resin

1980 ◽  
Vol 58 (8) ◽  
pp. 667-672 ◽  
Author(s):  
Luigi Toro ◽  
Domenico Gaudioso
Keyword(s):  
Mass Transfer ◽  
Liquid Phase ◽  
Particle Mass ◽  
Fluid Particle ◽  
Internal Diffusion ◽  
Kinetic Behavior ◽  
Surface Kinetics ◽  
Experimental Procedure ◽  
Porous Supports ◽  
Experimental Runs

An experimental procedure has been proposed to study liquid-phase reactions catalyzed by enzymes immobilized on porous supports. The kinetic behavior can be assessed by experimental runs which allow a separate evaluation of the internal diffusion, the surface kinetics, and the fluid-particle mass transfer. The method has been applied in the study of sucrose inversion by β-fructooxidase immobilized on IRA-93 resin.

Fluid - particle mass transfer in a packed bed

AIChE Journal ◽  
1961 ◽  
Vol 7 (1) ◽  
pp. 48-52 ◽  
Author(s):  
R. D. Bradshaw ◽  
C. O. Bennett
Keyword(s):  
Mass Transfer ◽  
Packed Bed ◽  
Particle Mass ◽  
Fluid Particle

Non-Newtonian fluid-particle mass transfer in granular beds

AIChE Journal ◽  
1983 ◽  
Vol 29 (4) ◽  
pp. 689-691 ◽  
Author(s):  
Y. Kawase ◽  
J. J. Ulbrecht
Keyword(s):  
Mass Transfer ◽  
Newtonian Fluid ◽  
Particle Mass ◽  
Fluid Particle

scholarly journals Mass Transfer of Anthocyanins during Extraction from Pre-Fermentative Grape Solids under Simulated Fermentation Conditions: Effect of Convective Conditions

Molecules ◽  
2018 ◽  
Vol 24 (1) ◽  
pp. 73 ◽  
Author(s):  
Patrick Setford ◽  
David Jeffery ◽  
Paul Grbin ◽  
Richard Muhlack
Keyword(s):  
Mass Transfer ◽  
Liquid Phase ◽  
Red Wine ◽  
Extraction Process ◽  
Internal Diffusion ◽  
Coefficient Of Determination ◽  
Convective Conditions ◽  
Transfer Coefficients ◽  
Liquid Phase Mass Transfer ◽  
Calculated Mass

The colour of red wine is largely determined by the concentration of anthocyanins that are extracted from grape skins during fermentation. Because colour is a key parameter in determining the overall quality of the finished product, understanding the effect of processing variables on anthocyanin extraction is critical for producing a red wine with the desired sensorial characteristics. In this study, the effect of convective conditions (natural and forced) on the mass transfer properties of malvidin-3-glucoside (M3G) from pre-fermentative grape solids was explored at various liquid phase conditions representing stages of fermentation. A mathematical model that separates solid and liquid phase mass transfer parameters was applied to experimental extraction curves, and in all cases, provided a coefficient of determination exceeding 0.97. Calculated mass transfer coefficients indicated that under forced convective conditions, the extraction process was controlled by internal diffusion whereas under natural convection, both internal diffusion and liquid-phase mass transfer were relevant in determining the overall extraction rate. Predictive simulations of M3G extraction during active fermentation were accomplished by incorporating the current results with a previously developed fermentation model, providing insight into the effect of a dynamic liquid phase on anthocyanin extraction.

Modeling of aerated upflow fixed bed reactors for nitrification

1999 ◽  
Vol 39 (4) ◽  
pp. 85-92 ◽  
Author(s):  
J. Behrendt
Keyword(s):  
Mathematical Model ◽  
Mass Transfer ◽  
Liquid Phase ◽  
Gas Phase ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Bulk Liquid ◽  
Initial Value ◽  
Fixed Bed Reactors ◽  
Number Of Cells

A mathematical model for nitrification in an aerated fixed bed reactor has been developed. This model is based on material balances in the bulk liquid, gas phase and in the biofilm area. The fixed bed is divided into a number of cells according to the reduced remixing behaviour. A fixed bed cell consists of 4 compartments: the support, the gas phase, the bulk liquid phase and the stagnant volume containing the biofilm. In the stagnant volume the biological transmutation of the ammonia is located. The transport phenomena are modelled with mass transfer formulations so that the balances could be formulated as an initial value problem. The results of the simulation and experiments are compared.

Heat and mass transfer during growth of a spherical particle from the liquid phase

1979 ◽  
Vol 37 (6) ◽  
pp. 1389-1393
Author(s):  
A. N. Verigin ◽  
I. A. Shchuplyak ◽  
M. F. Mikhalev ◽  
V. V. Varentsov
Keyword(s):  
Mass Transfer ◽  
Liquid Phase ◽  
Spherical Particle ◽  
Heat And Mass Transfer

Thermal convection in melting zone of hollow microparticle Al2O3

2021 ◽  
pp. 20-25
Author(s):  
V.V. Shekhovtsov ◽  
◽  
YU.A. Abzaev ◽  
O.G. Volokitin ◽  
A.A. Klopotov ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Numerical Modeling ◽  
Liquid Phase ◽  
Heat And Mass Transfer ◽  
Convective Heat ◽  
Thermal Convection ◽  
Melting Zone ◽  
Melting Front ◽  
Α Al2o3 ◽  
Inner Region

The paper presents the results of numerical modeling of development melting zone hollow spherical microparticle α-Al2O3. The object of the study was part circular sector, which represents the shell of hollow particle, which is formed under action plasma flow. Numerically describe the unsteady convective heat and mass transfer in shell hollow particle, we used the system Navier-Stokes equations in Boussinesq approximation, which describes the weak convection medium. Due to the high coefficient of porosity (P = 0.56) initial agglomerated particle with the α-Al2O3 structure, the inner region at the stage of heating Tp ≥ Tmelt is in the conditions heat exchange with the incoming heat flux, as result of which the temperature center coincided with the temperature particle surface. Result of overheating of the condensed phase, liquid layer of fused grains is formed in the inner and outer regions microparticle. In this case, the melting front is directed towards center shell. Result of numerical modeling, it has been established that convective heat and mass transfer is observed in melting zones (liquid phase), vector field of which covers almost the entire region of the liquid phase. It was found that thermal convection in the external liquid phase is characterized by velocities that are more than 2 times higher than the displacement velocity in the inner region of the particle. It is shown that there is no displacement of the material inside the convection region, thereby inhomogeneous heating occurs in the molten layer of the particle, which significantly affects the speed of movement of the melting front.

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