Course: CHE 432 – PROCESS DESIGN I (2 credits /Compulsory).
Course duration: 15 weeks (30hrs)
Lecturers:
1
Odetoye T.E.
Ph.D. Chemistry (Ilorin), M.Sc. Chemstry (Ilorin), B.Tech. Chemical Engineering, (Ogbomoso)
Email: odetoye.te@unilorin.edu.ng
Consultation hours: Tuesday 2 -3 pm
2
Ajala, O.E.
M.Sc. Chemical Engineering (Ile-Ife), B.Tech. Chemical Engineering (Ogbomoso),.
Email: ajala.oe@unilorin.edu.ng
Consultation hours: Wednesday 2 -3 pm
Location
1: Room 4: Chemical Engineering Building
2: Room 1: Chemical Engineering Building
Course Content
 Introduction to factors relating to process design
 Process diagrams: block diagrams, process flow diagram
 Process engineering diagrams
 Process instrumentation Diagrams (PID)
 Heat balances. Uses of Microsoft excel in calculating material and energy balances
 Use of commercial software (Chem CAD or Design 2000) in material and heat
balances calculations
 Economic analysis
 Pinch technology.
30h (T) PR CHE341 C
Course Description
Chemical Engineer is one who is skilled in development, design, construction and operation
of industrial plant. Chemical engineering design consists of process, equipment and building
designs for manufacturing plants to supply the product need of the consumers. Design is a
creative activity that is rewarding and satisfying when undertake by an engineer. It is the
synthesis, the putting together, of ideas to achieve a set goal. The design does not exist at the
beginning of the project. The designer starts with a specific objective in mind, a need, and by
developing and evaluating possible designs, arrives at what he considers the best way of
achieving that objective; for the chemical engineer, a new chemical product or a stage in the
design of a production process. The designer starts with the set of all possible solutions
bounded by the external constraints, and by a process of progressive evaluation and selection,
narrows down the range of candidates to find the “best” design for the purpose. The selection
process will become more detailed and more refined as the design progresses from the area of
possible to the area of probable solutions.
Course Justification:
Process and product design is the core responsibility of chemical engineer. It brings together
all the skills and knowledge acquired from other courses in the discipline to proffer solution
to the need of the consumers.
Course Objectives:
The general objective of the course as an integral part of the B.Sc. requirements in Chemical
Engineering is for the student to understand the applications of theoretical knowledge in the subject of
chemical engineering by applying to practical work.
Course Requirements:
This is a compulsory course for all Chemical Engineering students. In view of this, students
are expected to have minimum of 75% attendance to be able to write the final examination.
Methods of grading:
No
1
2
3
Item
CA (Quiz, Assignment, Test etc)
Examination
Total
Score %
30
70
100
Course Delivery Strategies:
The lecture will be delivered through face-to-face method. The students will be required to
read around the topics.
LECTURES
Week 1-2: Introduction to factors relating to process design, process diagrams: block
diagrams, process flow diagram, process engineering diagrams
Objective: This is to introduce the student to the basic concept of process design. To teach
them process engineering diagrams.
Description: Design specification includes some factors which must be considered
favourably before setting in motion design work. These factors would create a margin of
safety in the design; safety in the sense of equipment failure and safety in the sense of
equipment perform below satisfactory. “Design factor” is a better term to use as it does not
confuse safety and performance factors. The ideas which develop the chemical and physical
picture of the process are set on drawing with simple block or box diagrams.
Study Questions
With detail drawing, explain heat exchanger.
2. Use block diagram to describe this process;
1.
Reading list
1. Martyn S. Ray and David W. Johnston, Chemical Engineering Design Project: A case
Study Approach. Bell and Bain Ltd., Glasgow Publication, 1989, pp 1 – 3.
2. Richardson and Coulson, Chemical Engineering Design, Vol 6, 4th Ed., Elsevier
Publication, 2006, pp. 1 – 4.
Week 3: Process instrumentation Diagrams (PID)
Objective: To review process diagram symbols. To describe the use of process diagrams and
the information they contain. To teach students how to draw a process flow diagram and
process instrument drawing. This course would also describe the various process equipment
relationships.
Description: Process instrumentation diagrams (PID) is the pictorial representation of a
process which shows the interconnection of process equipment and the instrumentation used
to control the process. In the process industry, a standard set of symbols is used to prepare
drawings of processes. The instrument symbols used in these PIDs are generally based on
International Society of Automation. PIDs play a significant role in the maintenance and
modification of the process that it describes. It is critical to demonstrate the physical
sequence of equipment and systems, as well as how these systems connect. During the design
stage, the diagram also provides the basis for the development of system control schemes,
allowing for further safety and operational investigations, such as the hazard and operability
study (HAZOP).
Study Questions
1. Describe a process flow diagram and a process and instrument drawing.
2. Draw the symbols for a gate, globe, and automatic valve.
3. Draw the symbols for a centrifugal pump and positive displacement pump.
4. Draw the symbols for a blower and a reciprocating compressor.
5. Draw the symbols for a steam turbine and centrifugal compressor.
6. Draw the symbols for a heat exchanger and a cooling tower.
7. Draw the symbols for a packed distillation column and plate distillation column.
8. Draw the symbols for a furnace and a boiler.
Reading list
1. Martyn S. Ray and David W. Johnston, Chemical Engineering Design Project: A case
Study Approach. Bell and Bain Ltd., Glasgow Publication, 1989.
2. Richardson and Coulson, Chemical Engineering Design, Vol 6, 4th Ed., Elsevier
Publication, 2006.
Week 4 - 6: Materials and Energy Balance: The Use of Computer Software
Objective: To teach student the use of computer software to solve material and energy
balance problems
Description: Material balances are the basis of process design. Material balance is an
application of law of conservation of matter. This account for every substance used in a
process and show location within the process where each substance is converted,
accumulated or discharge. Every change in the material balance must be reflected in the
process and in the mechanical design. Energy balance is similar to material balance in
preparation but only relate to the quantity of energy (heat) utilised or released with relevant
temperature of each stream and equipment within a process. In the time past when solving
problem related to this topic, it used to be rigorous mathematical exercise. Now with the
advent of software development, the entire problem related to Material and Energy balance
could be solved using relevant computer software.
Study Questions:
1. Technical grade hydrochloric acid has strength of 28 per cent w/w; express this as a
mol fraction.
2. 2000 kg of 5 per cent slurry of calcium hydroxide in water is to be prepared by
diluting 20 per cent slurry. Calculate the quantities required. The percentages are by
weight.
3. The ideal state heat capacity of ethylene is given by the equation:
𝐶𝑝𝑜 = 3.95 + 15.6 X 10-2T – 8.3 X 10-5T2 + 17.6 X 10-9T3 J/mol K
Estimate the value at 10 bar and 300 K.
4. Calculate the maximum temperature when liquid ammonia at 40oC is dissolved in
water at 20oC to form a 10 per cent solution.
5. A furnace burns a liquid coal tar fuel derived from coke-ovens. Calculate using
Microsoft excel spreadsheet, the heat transferred in the furnace if the combustion
gases leave at 1500K. The burners operate with 20 per cent excess air. Take the fuel
supply temperature as 50oC (323K) and the air temperature as 15oC (288K).
The properties of the fuel are:
Carbon
87.5 per cent w/w
Hydrogen
8.0
Oxygen
3.5
Nitrogen
1.0
Sulphur
trace Ash
balance
Net calorific value
39,540 kJ/kg
Latent heat of vaporisation 350 kJ/kg
Heat capacity
1.6 kJ/kg
𝒐
𝑪𝒑 of gases, kJ/kmol K,
Cp = A + BT + CT2 + DT3
Component
1. CO2
2. H2O
3. O2
4. N2
A
19.763
32.190
28.06
31.099
B
7.332E-2
19.207E-4
-3.674E-6
-1.354E-2
C
-5.518E-5
10.538E-6
17.431E-6
26.752E-6
D
17.125E-9
-3.591E-9
-10.634E-9
-11.662E-9
Reading list
1. Richardson and Coulson, Chemical Engineering Design, Vol 6, 4th Ed., Elsevier
Publication, 2006, pp.34 – 122.
2. Martyn S. Ray and David W. Johnston, Chemical Engineering Design Project: A case
Study Approach. Bell and Bain Ltd., Glasgow Publication, 1989, pp 106 – 137.
Week 7 - 10: Economic Analysis
Objective: To teach the students capital and manufacturing cost estimation break – even
analysis; depreciation, discounted cash flows, rate of return on investment, discounted cash
flow rate of return, sensitivity and process costing.
Description: In the preliminary stage of design project, approximate cost estimates are
required and usually in the minimum time possible. Cost correlations and factored estimates
are usually sufficiently accurate for the initial cost estimation study, and they significantly
reduce the calculation time required for more detailed estimates. Detailed cost estimates are
usually required after the detailed design work has been completed, including the design and
sizing of all equipment, determination of pipe work layouts, and specification of the control
and instrumentation schemes. The additional time and effort required to produce a more
accurate cost estimate is rarely justified in the preliminary stage of the design.
Reading List:
1. Martyn S. Ray and David W. Johnston, Chemical Engineering Design Project: A case
Study Approach. Bell and Bain Ltd., Glasgow Publication, 1989.
2. Richardson and Coulson, Chemical Engineering Design, Vol 6, 4th Ed., Elsevier
Publication, 2006.
Week 11 - 14: Pinch technology.
Objective: To teach students the concept and application of the pinch technology in
industrial process design.
Description: Pinch analysis is a new thermodynamic concept where a proper analysis of
Process Heat Exchange. Appropriate Thermodynamic analysis also leads to identification of
preferred options in terms of many other design objectives, for example, minimization of
capital cost and operational cost. Pinch technology is a process integration technique and a
powerful way to optimize the process design, yielding results better than achievable by using
conventional optimization of processes in isolation, tends to optimize the system (a collection
of interrelated processes and unit operations) as a whole. Application of pinch technology in
pulp & paper industry has provided innovative ways to reduce the energy consumption in
pulp & paper manufacturing processes. Also in petroleum refinery, rate of energy
consumption has been drastically reduced by the use of pinch technology. Reduced energy
consumption is one of the beneficial aspects of the pinch technology.
Reading List:
1. R.M. Mathur, B.P. Thapliyal, Alok Goel, S. S. Dixit, Sanjay Tyagi, V. K. Bhorale and
A.G.Kulkarni (). Process Integration through Pinch Analysis: A Concept Central Pulp
and Paper Research Institute, Saharanpur
Week 15: Revision and Examination