scholarly journals Heat and Mass Transfer in Packed Bed Drying of Shrinking Particles

10.5772/14916 ◽  
2011 ◽  
Author(s):  
Manoel Marcelo do Prado ◽  
Dermeval Jos Mazzini Sartori
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Packed Bed

scholarly journals Analysis of Entropy Production in Structured Chemical Reactors: Optimization for Catalytic Combustion of Air Pollutants

Entropy ◽  
2020 ◽  
Vol 22 (9) ◽  
pp. 1017 ◽  
Author(s):  
Mateusz Korpyś ◽  
Anna Gancarczyk ◽  
Marzena Iwaniszyn ◽  
Katarzyna Sindera ◽  
Przemysław J. Jodłowski ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Entropy Production ◽  
Heat And Mass Transfer ◽  
Chemical Reaction ◽  
Catalytic Combustion ◽  
Packed Bed ◽  
Optimization Criterion ◽  
Rational Solutions ◽  
Short Channel ◽  
Flow Friction

Optimization of structured reactors is not without some difficulties due to highly random economic issues. In this study, an entropic approach to optimization is proposed. The model of entropy production in a structured catalytic reactor is introduced and discussed. Entropy production due to flow friction, heat and mass transfer and chemical reaction is derived and referred to the process yield. The entropic optimization criterion is applied for the case of catalytic combustion of methane. Several variants of catalytic supports are considered including wire gauzes, classic (long-channel) and short-channel monoliths, packed bed and solid foam. The proposed entropic criterion may indicate technically rational solutions of a reactor process that is as close as possible to the equilibrium, taking into account all the process phenomena such as heat and mass transfer, flow friction and chemical reaction.

Heat and Mass Transfer Characteristics in Adsorption of Water Vapor for Silica Gel Packed Bed Adsorber.

2000 ◽  
Vol 33 (1) ◽  
pp. 12-18 ◽  
Author(s):  
Eri Yamamoto ◽  
Koichi Katsurayama ◽  
Fujio Watanabe ◽  
Hitoki Matsuda ◽  
Masanobu Hasatani
Keyword(s):  
Mass Transfer ◽  
Water Vapor ◽  
Heat And Mass Transfer ◽  
Silica Gel ◽  
Packed Bed ◽  
Transfer Characteristics ◽  
Adsorption Of Water ◽  
Adsorption Of Water Vapor

scholarly journals A Study of Steady Buoyancy-Driven Dissipative Micropolar Free Convection Heat and Mass Transfer in a Darcian Porous Regime with Chemical Reaction

2007 ◽  
Vol 12 (2) ◽  
pp. 157-180 ◽  
Author(s):  
O. Anwar Bég ◽  
R. Bhargava ◽  
S. Rawat ◽  
H. S. Takhar ◽  
Tasweer A. Bég
Keyword(s):  
Mass Transfer ◽  
Velocity Field ◽  
Heat And Mass Transfer ◽  
Chemical Reaction ◽  
Reaction Rate ◽  
Near Field ◽  
Packed Bed ◽  
Darcy Number ◽  
Reaction Model ◽  
Chemical Reaction Rate

In the present paper we examine the steady double-diffusive free convective heat and mass transfer of a chemically-reacting micropolar fluid flowing through a Darcian porous regime adjacent to a vertical stretching plane. Viscous dissipation effects are included in the energy equation. Assuming incompressible, micro-isotropic fluid behaviour the transport equations are formulated in a two-dimensional coordinate system (x, y) using boundary-layer theory. The influence of the bulk porous medium retardation is modeled as a drag force term in the translational momentum equation. Transformations render the conservation equations into dimensionless form in terms of a single independent variable, η, transverse to the stretching surface. A simplified first order homogenous reaction model is also used to simulate chemical reaction in the flow. Using the finite element method solutions are generated for the angular velocity field, translational velocity field, temperature and species transfer fields. The effects of buoyancy, porous drag and chemical reaction rate are studied. Chemical reaction is shown to decelerate the flow and also micro-rotation values, in particular near the wall. Mass transfer is also decreased with increasing chemical reaction rate. Increasing Darcy number is shown to accelerate the flow. Applications of the study include cooling of electronic circuits, packed-bed chemical reactors and also the near field flows in radioactive waste geo-repositories.

scholarly journals Revisiting the Role of Mass and Heat Transfer in Gas–Solid Catalytic Reactions

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1599
Author(s):  
Riccardo Tesser ◽  
Elio Santacesaria
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Kinetic Studies ◽  
Packed Bed ◽  
Catalytic Reactions ◽  
Catalytic Reactors ◽  
Tremendous Progress ◽  
Mass And Heat Transfer ◽  
Energy Balances

The tremendous progress in the computing power of modern computers has in the last 20 years favored the use of numerical methods for solving complex problems in the field of chemical kinetics and of reactor simulations considering also the effect of mass and heat transfer. Many classical textbooks dealing with the topic have, therefore, become quite obsolete. The present work is a review of the role that heat and mass transfer have in the kinetic studies of gas–solid catalytic reactions. The scope was to collect in a relatively short document the necessary knowledge for a correct simulation of gas–solid catalytic reactors. The first part of the review deals with the most reliable approach to the description of the heat and mass transfer outside and inside a single catalytic particle. Some different examples of calculations allow for an easier understanding of the described methods. The second part of the review is related to the heat and mass transfer in packed bed reactors, considering the macroscopic gradients that derive from the solution of mass and energy balances on the whole reactor. Moreover, in this second part, some examples of calculations, applied to chemical reactions of industrial interest, are reported for a better understanding of the systems studied.

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