Corrugated surfaces such as those shown schematically in the figure below are commonly encountered in chemical systems. Examples include roughness evolution in metal deposition, catalysis, and surface polishing. These systems present interesting diffusion-reaction problems wherein species diffusion into the surface cavities is coupled with reactions. Your task is to analyze the special case of steady-state diffusion and 1st order reaction following the steps below: (a) Setup a mass balance on an infinitesimally small volume element (thickness Az and width x) shown in grey color in the schematic below. Using the relationship x = a(L-z)/L (for a triangular shaped cavity) depicted in the inset below and assuming that the sidewalls are nearly vertical (0 is very small), clearly show how you can derive the differential mass balance equation: 2kL C=0 Da where C is the species concentration that varies only in the z-direction, k is the 1st order reaction

Introduction to Chemical Engineering Thermodynamics
8th Edition
ISBN:9781259696527
Author:J.M. Smith Termodinamica en ingenieria quimica, Hendrick C Van Ness, Michael Abbott, Mark Swihart
Publisher:J.M. Smith Termodinamica en ingenieria quimica, Hendrick C Van Ness, Michael Abbott, Mark Swihart
Chapter1: Introduction
Section: Chapter Questions
Problem 1.1P
icon
Related questions
Question
100%
Corrugated surfaces such as those shown schematically in the figure below are commonly
encountered in chemical systems. Examples include roughness evolution in metal deposition,
catalysis, and surface polishing. These systems present interesting diffusion-reaction problems
wherein species diffusion into the surface cavities is coupled with reactions. Your task is to
analyze the special case of steady-state diffusion and 1st order reaction following the steps
below:
(a) Setup a mass balance on an infinitesimally small volume element (thickness Az and width x)
shown in grey color in the schematic below. Using the relationship x = a(L-z)/L (for a triangular
shaped cavity) depicted in the inset below and assuming that the sidewalls are nearly vertical (0
is very small), clearly show how you can derive the differential mass balance equation:
2kL
C= 0
Da
where C is the species concentration that varies only in the z-direction, k is the 1st order reaction
rate constant, and D is the diffusion coefficient of the diffusing species.
a
diffusion
+ reaction
z+Az
x = a(1-/L)
e is very small,
so that cos 8=1
Transcribed Image Text:Corrugated surfaces such as those shown schematically in the figure below are commonly encountered in chemical systems. Examples include roughness evolution in metal deposition, catalysis, and surface polishing. These systems present interesting diffusion-reaction problems wherein species diffusion into the surface cavities is coupled with reactions. Your task is to analyze the special case of steady-state diffusion and 1st order reaction following the steps below: (a) Setup a mass balance on an infinitesimally small volume element (thickness Az and width x) shown in grey color in the schematic below. Using the relationship x = a(L-z)/L (for a triangular shaped cavity) depicted in the inset below and assuming that the sidewalls are nearly vertical (0 is very small), clearly show how you can derive the differential mass balance equation: 2kL C= 0 Da where C is the species concentration that varies only in the z-direction, k is the 1st order reaction rate constant, and D is the diffusion coefficient of the diffusing species. a diffusion + reaction z+Az x = a(1-/L) e is very small, so that cos 8=1
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 3 steps

Blurred answer
Similar questions
Recommended textbooks for you
Introduction to Chemical Engineering Thermodynami…
Introduction to Chemical Engineering Thermodynami…
Chemical Engineering
ISBN:
9781259696527
Author:
J.M. Smith Termodinamica en ingenieria quimica, Hendrick C Van Ness, Michael Abbott, Mark Swihart
Publisher:
McGraw-Hill Education
Elementary Principles of Chemical Processes, Bind…
Elementary Principles of Chemical Processes, Bind…
Chemical Engineering
ISBN:
9781118431221
Author:
Richard M. Felder, Ronald W. Rousseau, Lisa G. Bullard
Publisher:
WILEY
Elements of Chemical Reaction Engineering (5th Ed…
Elements of Chemical Reaction Engineering (5th Ed…
Chemical Engineering
ISBN:
9780133887518
Author:
H. Scott Fogler
Publisher:
Prentice Hall
Process Dynamics and Control, 4e
Process Dynamics and Control, 4e
Chemical Engineering
ISBN:
9781119285915
Author:
Seborg
Publisher:
WILEY
Industrial Plastics: Theory and Applications
Industrial Plastics: Theory and Applications
Chemical Engineering
ISBN:
9781285061238
Author:
Lokensgard, Erik
Publisher:
Delmar Cengage Learning
Unit Operations of Chemical Engineering
Unit Operations of Chemical Engineering
Chemical Engineering
ISBN:
9780072848236
Author:
Warren McCabe, Julian C. Smith, Peter Harriott
Publisher:
McGraw-Hill Companies, The