Catalytic Reaction Engineering – CHEN30051&30041&30251: Coursework Assignment 1

Catalytic Reaction Engineering
CHEN 30051 & 30041 & 30251
Coursework:
Continuous Assessment Task

This coursework is related to the following ILOs:
x ILO4 – Apply analytical and numerical methods to determine reactor behaviour and analyse the results.
x ILO5 – Design (size) heterogeneous chemical reactor and optimise operating conditions.
The aim of this coursework is for you to understand how we can apply the fundamental basics
of CRE to chemical engineering design, and to undertake extra research into the design of a
packed bed reactor system.
This coursework is mainly focused on Topic 4 (Software packages as a tool in reactor design)
and Topic 5 (Solid-fluid reactor design - Packed bed reactors). The coursework is worth 30%
of the unit assessment.
Further reading:
x Fogler, Elements of Chemical Reaction Engineering, 5th Edition.
x Luyben, Chemical Reactor Design and Control, 2007.


1. Introduction
Consider the elementary heterogeneous gas phase catalytic reaction in an ideal packed-bed
reactor:
A + B o C
The rate of reaction is given by:
−
′ = ′ (in kmol s–1 kg-catalyst –1)
where PA and PB are the partial pressures (in bar) of A and B respectively and k’ is the
specific rate constant (in kmol s–1 bar –2 kg-catalyst –1).



Catalytic Reaction Engineering – CHEN30051&30041&30251: Coursework Assignment 2

Table 1. Key kinetic and physical parameters.
Heat of reaction 'HR kJ kmol–1 -23,237
Activation energy E kJ kmol–1 69,710
Pre-exponential factor A kmol s–1 bar–2 (kg-catalyst) –1 0.19038
Heat capacities CPA kJ kmol–1 K-1 30
CPB kJ kmol–1 K-1 40
CPC kJ kmol–1 K-1 70
Molecular weights MA kg kmol–1 15
MB kg kmol–1 20
MC kg kmol–1 35
Gas viscosity P kg m–1 s–1 0.18 x 10–4
Heat transfer coefficient U kW m–2 K–1 0.227

Table 2. Operating and design parameters (unique for each group).
Inlet Conditions:
Pressure P0 bar
Temperature T0 K
Total molar inlet flow rate FT0 kmol s–1
mol-fraction of A yA0 -
mol-fraction of B yB0 -
Catalyst Properties:
Porosity (void fraction) I -
Catalyst particle size Dp m
Catalyst bulk density Ucatalyst, bulk kg m–3
Reactor Information:
Reactor diameter Dreactor m
Reactor length Lreactor m
Cooling temperature Ta K




4 . 6
357
0 . 62
0 . 37
0. 63
0. 46
00 15
000
Catalytic Reaction Engineering – CHEN30051&30041&30251: Coursework Assignment 3

2. Assignment
2.1 Main task
Develop and design packed bed reactor units for the following three scenarios:
CASE A: Single adiabatic PBR
CASE B: Adiabatic reactor with interstage cooling
CASE C: Cooled PBR with constant cooling medium temperature
The following information should be included:
x Justification of various underlying assumptions used in making the design calculations.
x Justification that the design will work, e.g., does it follow key rules of thumb.
x Develop of source code: user-friendly (including comments, guidance etc.) for reuse by
another design engineer and effectiveness in coding methods.
x Profile plots for temperature, composition, conversion, pressure, etc. down the length of
the reactor.
Analyse and evaluation of each case should be discussed from an operational and
economic viewpoint:
CASE A: Single adiabatic PBR
Use the operating and design parameters provided to your group in Table 2
and discuss the effect of the following variables on the different profiles:
x Inlet temperature is varied.
x Inlet pressure is varied.
x Particle diameter is changed: Consider at what particle size pressure
drop becomes important for the same catalyst weight (assume the
porosity doesn’t change).
x Reactor diameter and length is changed for the same overall weight of
catalyst.
CASE B: Adiabatic reactor with interstage cooling
Use two (2) cooling stages with the same conditions as in CASE A (same
overall weight of catalyst) and discuss the effect of the following variables on
the profiles:
x Cooling temperature: How does the temperature of the cooling in each
stage effect the profiles?
x Inlet temperature is varied.
x Reactor diameter and length is changed (keeping the catalyst weight
the same).
CASE C: Cooled PBR with constant cooling medium temperature
Use the same conditions as in CASE A (same overall weight of catalyst) but
with a cooling temperature Ta and discuss the effect of the following variables
on the profiles:
x Cooling temperature is varied.
x Inlet temperature is varied.
x Reactor diameter and length is changed (keeping the catalyst weight
the same).
Catalytic Reaction Engineering – CHEN30051&30041&30251: Coursework Assignment 4

2.2 Deliverables
Specifically, you are to prepare the following for submission (submission will be done through
blackboard):
1. A written coursework report.
Please submit your report file as “_report.pdf”, example for the group
Gary it will be Gary_report.pdf.
2. A copy of your source code (Matlab/Python/Polymath).
Please submit all relevant code files that clearly include your groupname.
2.3 Written report
One report should be submitted per group. The written report should comply to the page limit
for each section. Formatting should be Arial-font, font size 11, line spacing single and text
alignment as justified. The following sections should at least be included:
x Title page (maximum 1 page)
o Group name and number
o Students names and numbers (alphabetical order)

x Section 1 – Results and Discussion: Case A (maximum of 2 pages)
This section presents all the relevant results obtained and interpretation thereof
for Case A.

x Section 2 – Results and Discussion: Case B (maximum of 2 pages)
This section presents all the relevant results obtained and interpretation thereof
for Case B.

x Section 3 – Results and Discussion: Case C (maximum of 2 pages)
This section presents all the relevant results obtained and interpretation thereof
for Case C.

x Section 4 –Discussion: (maximum of 2 pages)
Discuss advantages and disadvantages of all the cases together from an
operational and economic standpoint. Are there any alternative configurations to
consider? Draw a flowsheet for one of the CASE B or CASE C that include ancillary
equipment.
.
x Section 5 – Source code and file names submitted (no page limits)
This section presents all the source code develop to solve the coursework and
the relevant file names. Only source code.

Please keep to the report section lengths; if the section lengths are exceeded, when marking
we will stop marking that section at the page limit.



Catalytic Reaction Engineering – CHEN30051&30041&30251: Coursework Assignment 5

3. Assessment Criteria
The coursework will be evaluated according to the following main criteria in the design report:
1. Analysis and Evaluation of Scenarios
i. Discussion on CASE A
ii. Discussion on CASE B
iii. Discussion on CASE C
iv. Discussion on all cases
2. Effective Communication of Design Report.
3. Code to solve ODEs
After completion of this assessment the group will receive feedback on their performance in
the form of a feedback report that looks like the one given below:

Group Name:
Criteria of evaluation Assessment weighting
Group
mark / %
Design Report-
1. Analysis and Evaluation of Scenarios:
i. CASE A 15%
ii. CASE B 15%
iii. CASE C 15%
iv. All cases 15%
2. Overall Structure, Style, and Presentation 20%
3. Code to Solve ODEs* 20%
Total: 100%
*Take note your welcome to use any software such as MATLAB, Python, Polymath, etc.


Catalytic Reaction Engineering – CHEN30051&30041&30251: Coursework Assignment 6

Criteria 1: Analysis and Evaluation of Scenarios
Range Description CASE A Mark
CASE B
Mark
CASE C
Mark
ALL
CASES
High 1st
(≥80%)
Exceptional representation of results with
figures and/or tables that are clear, easy to read,
consistent and aid effective communication. The
discussion part demonstrates a high level of
critical evaluation that is supported with
insightful and comprehensive interpretation and
deep understanding of the results. High-quality
analysis of constrains justification. The results
are rigours and very convincing sound/valid.

1st
(70%-79%)
Good representation of the results with figures
and/or tables that are clear, easy to read,
consistent and aid effective communication. The
discussion part demonstrates a good critical
evaluation that is supported with insightful
interpretation and understanding of the results.
Strong independent lines of argument
presented. High level of discussion and analysis
of constrains. The results are sound/valid.

Upper 2nd
(60%-69%)
Good representation of results with figures
and/or tables that are clear, easy to read,
consistent and aid effective communication. The
discussion part demonstrates a good evaluation
of results with adequate interpretation and
understanding. Adequate analysis and
justification of results, assumptions and
calculations with some faults/shortcomings.
The results are arguable convincing.

Lower 2nd
(50%-59%)
The results are adequately representation with
figures and/or tables that are clear, easy to read,
consistent and aid effective communication. The
results are adequately explained. Some
conceptual ability and grasp of analysis and
justification. Calculations with few weaknesses.
The results are nearly plausible.

Pass/3rd
(40%-49%)
Representation of the results with figures and/or
tables is reasonably clear and easy to follow.
Basic level of analysis and justification of results
and calculations with some significant
weaknesses. Some errors in the results and
interpretation are evident.

Fail (<40%)
Bad or no attempt of presenting the results.
Inability to obtain solutions using standard
design procedures, rules of thumb, etc.
Insufficient analysis and justification or no
attempt of presenting analysis and calculations.
Superficial understanding of concepts and
significant gaps and/or errors in the results.

Comments


Catalytic Reaction Engineering – CHEN30051&30041&30251: Coursework Assignment 7

Criteria 2: Overall Structure, Style, and Presentation
Range Description Mark
High 1st
(≥80%)
Exceptional quality that is highly reader-friendly and contains no grammatical
or spelling mistakes.

1st
(70%-79%)
Excellent written report with almost no blunders. There is a high level of
coherence throughout the report, with a clear flow and logical links between
the sections. All the figures and tables are clear and aid effective
communication.

Upper 2nd
(60%-69%)
Good written report with a clear English style, minor grammar, and spelling
mistakes. Structure, figures, and tables are clear, consistent and aid effective
communication.

Lower 2nd
(50%-59%)
Adequately written report with several grammar and spelling mistakes.
Inconsistencies in structure but the majority of the report retains a clear
exposition that can be followed and understood.

Pass/3rd
(40%-49%)
The report is poorly written with poor grammar, many spelling mistakes and
little attempt to adhere to the instructions. Errors impede effective
communication.

Fail (<40%) The report is badly written that is lacking in logical structure, difficult to read and no attempt has been made to adhere to the instructions for the report.

Comments

Criteria 3: Code to solve ODEs
Range Description Mark
High 1st
(≥80%)
The numerical source code is working with no errors. Source code
representation is excellent, clear and easy to following with detail comments
and guidance new users. An exceptional way of code developed that is well-
structured, easy to follow and user friendly to change for different scenarios.
(The numerical results are very convincing sound/valid.)

1st
(70%-79%)
The numerical source code is working with no errors. Good source code
representation that is clear and easy to following with comments for guidance.
A user-friendly way of code development for analysis purposes.
(The numerical results are very convincing sound/valid.)

Upper 2nd
(60%-69%)
The numerical source code is working with no errors. The code is clear and
easy to following (generally user-friendly) with some comments.
(The numerical results are arguably valid.)

Lower 2nd
(50%-59%)
The numerical source code is working with minor mistakes. Source code is
clear and adequate to follow and understand.
(The results are nearly plausible.)

Pass/3rd
(40%-49%)
The source code is poor (incorrect) with significant gaps or errors.
Fail (<40%) No source code (software-files) is handed in or the source code is very bad (do not work) with major errors and gaps.
Comments