1. [Biofilter] A biofilter has been chosen for eliminating odour problems around a process plant. The odorous compound is present in an exhaust air with an average flow rate of 12.5 m³/s and concentration of 3810 ppbv. The concentration must be decreased to 500 ppbv to meet the consent standards. The dimensionless Henry's constant for the odorous compound is 0.11 and the reaction coefficient is 0.15 min-1. The degradation reaction follows first-order kinetics. From analysis of other biofilters, it is known that acceptable face velocities are 35-80 m/h. Estimate the range of filter bed heights needed to ensure the consent standards are met. [Ans: 0.87-1.99 m]
1. [Biofilter] A biofilter has been chosen for eliminating odour problems around a process plant. The odorous compound is present in an exhaust air with an average flow rate of 12.5 m³/s and concentration of 3810 ppbv. The concentration must be decreased to 500 ppbv to meet the consent standards. The dimensionless Henry's constant for the odorous compound is 0.11 and the reaction coefficient is 0.15 min-1. The degradation reaction follows first-order kinetics. From analysis of other biofilters, it is known that acceptable face velocities are 35-80 m/h. Estimate the range of filter bed heights needed to ensure the consent standards are met. [Ans: 0.87-1.99 m]
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
Related questions
Question
show working on how to reach answers
![Parameter
ommon parameters used to describe blofilters and their performance
Empty bed residence time
(EBRT)
Volumetric mass loading
[mass/(volume x time)]
(e.g.: g m-³ s-¹)
Removal efficiency (RE or n)
Elimination capacity (EC)
[mass/(volume × time)]
(e.g.: g m-³ s-¹)
Equation
EBRT =
Vf
Qg
Vol mass loading
RE=n=
EC =
=
Cin - Cout
Cin
Qg (Cin-Cout)
Vf
Qg Cin
Vf
Biofiltration
Comments
n = 1 - exp
Allows estimation of filter size for
a given flowrate of waste gas
V₁=filter bed volume
Qg = volumetric flowrate of waste gas
Cin = inlet mass concentration of contaminant
(substance to degrade)
If flow remains constant through a filter, the
mass loading along the length of the filter bed
will decline as contaminant is removed.
Cout= mass concentration of contaminant at
outlet of biofilter
Mass of contaminant degraded per unit
volume of filter material per unit time
EC= volumetric mass loading X RE
The mass transfer of contaminant from the gas to the water phase is generally
not the rate-limiting step, so gas and liquid can be assumed at equilibrium.
Partition between gas and liquid phases is generally described by Henry's law.
11
Assuming a first-order kinetics (valid for low concentrations of pollutant) the
removal efficiency in a biofilter can be given by:
Zk
Кн и
where:
Z = biofilter bed height
KH = Henry's Law constant
u = superficial velocity of the gas (= Q/A, no need to use the porosity of the biofilter bed)
k = empirical reaction term](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2Fde55ad6b-27eb-44c5-bca1-afdb32f2dfc7%2Fc242309e-921c-4d45-a365-b72e8fb15c4b%2Fyj2qcx_processed.png&w=3840&q=75)
Transcribed Image Text:Parameter
ommon parameters used to describe blofilters and their performance
Empty bed residence time
(EBRT)
Volumetric mass loading
[mass/(volume x time)]
(e.g.: g m-³ s-¹)
Removal efficiency (RE or n)
Elimination capacity (EC)
[mass/(volume × time)]
(e.g.: g m-³ s-¹)
Equation
EBRT =
Vf
Qg
Vol mass loading
RE=n=
EC =
=
Cin - Cout
Cin
Qg (Cin-Cout)
Vf
Qg Cin
Vf
Biofiltration
Comments
n = 1 - exp
Allows estimation of filter size for
a given flowrate of waste gas
V₁=filter bed volume
Qg = volumetric flowrate of waste gas
Cin = inlet mass concentration of contaminant
(substance to degrade)
If flow remains constant through a filter, the
mass loading along the length of the filter bed
will decline as contaminant is removed.
Cout= mass concentration of contaminant at
outlet of biofilter
Mass of contaminant degraded per unit
volume of filter material per unit time
EC= volumetric mass loading X RE
The mass transfer of contaminant from the gas to the water phase is generally
not the rate-limiting step, so gas and liquid can be assumed at equilibrium.
Partition between gas and liquid phases is generally described by Henry's law.
11
Assuming a first-order kinetics (valid for low concentrations of pollutant) the
removal efficiency in a biofilter can be given by:
Zk
Кн и
where:
Z = biofilter bed height
KH = Henry's Law constant
u = superficial velocity of the gas (= Q/A, no need to use the porosity of the biofilter bed)
k = empirical reaction term
![1. [Biofilter] A biofilter has been chosen for eliminating odour problems around a process plant. The
odorous compound is present in an exhaust air with an average flow rate of 12.5 m³/s and
concentration of 3810 ppbv. The concentration must be decreased to 500 ppbv to meet the
consent standards. The dimensionless Henry's constant for the odorous compound is 0.11 and
the reaction coefficient is 0.15 min-1. The degradation reaction follows first-order kinetics.
From analysis of other biofilters, it is known that acceptable face velocities are 35-80 m/h.
Estimate the range of filter bed heights needed to ensure the consent standards are met.
[Ans: 0.87-1.99 m]](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2Fde55ad6b-27eb-44c5-bca1-afdb32f2dfc7%2Fc242309e-921c-4d45-a365-b72e8fb15c4b%2Fm42g0xs_processed.png&w=3840&q=75)
Transcribed Image Text:1. [Biofilter] A biofilter has been chosen for eliminating odour problems around a process plant. The
odorous compound is present in an exhaust air with an average flow rate of 12.5 m³/s and
concentration of 3810 ppbv. The concentration must be decreased to 500 ppbv to meet the
consent standards. The dimensionless Henry's constant for the odorous compound is 0.11 and
the reaction coefficient is 0.15 min-1. The degradation reaction follows first-order kinetics.
From analysis of other biofilters, it is known that acceptable face velocities are 35-80 m/h.
Estimate the range of filter bed heights needed to ensure the consent standards are met.
[Ans: 0.87-1.99 m]
Expert Solution
This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
Step by step
Solved in 3 steps with 2 images
Recommended textbooks for you
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…
Chemical Engineering
ISBN:
9781118431221
Author:
Richard M. Felder, Ronald W. Rousseau, Lisa G. Bullard
Publisher:
WILEY
Elements of Chemical Reaction Engineering (5th Ed…
Chemical Engineering
ISBN:
9780133887518
Author:
H. Scott Fogler
Publisher:
Prentice Hall
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…
Chemical Engineering
ISBN:
9781118431221
Author:
Richard M. Felder, Ronald W. Rousseau, Lisa G. Bullard
Publisher:
WILEY
Elements of Chemical Reaction Engineering (5th Ed…
Chemical Engineering
ISBN:
9780133887518
Author:
H. Scott Fogler
Publisher:
Prentice Hall
Industrial Plastics: Theory and Applications
Chemical Engineering
ISBN:
9781285061238
Author:
Lokensgard, Erik
Publisher:
Delmar Cengage Learning
Unit Operations of Chemical Engineering
Chemical Engineering
ISBN:
9780072848236
Author:
Warren McCabe, Julian C. Smith, Peter Harriott
Publisher:
McGraw-Hill Companies, The