1. Chemical Process Development (Scale up issue in chemical industry)
A. Hisyam
Faculty of Chemical and Natural Resources Engineering
University Malaysia Pahang

2. Resources
E. Tirronen and T. Salmi, Chemical Engineering Journal 91 (2003)
G. Donati and R. Paludetto, Catalysis Today 34 (1997)

3. Chemical process development may have one of the following objectives
Design and construction of a new plant (grass root designing)
The design and development of a new process for an old process (modernizing an existing plant)
Modifications and additions to existing plant; usually carried out by the plant design group (process modification)

4. Phases of chemical process development
Conceptual chemical phase
Conceptual process development phase
Chemical and process development phase and process engineering phase
Commissioning and start up phase

5. Conceptual chemical phase
Identification of different chemical routes
Do you know how many ways we can produce eugenol from clove oil?
Generation of alternative chemical synthesis pathways process schemes
Find other possible ways to produce ethanol other than fermentation from glucose
Preliminary experiments
Preliminary process scheme
Preliminary cost estimation

6. Conceptual process development phase
Mass balance
Preliminary heat balance
Preliminary block diagram and flowsheet
Gantt Chart for scheduling
Production capacity
Cost estimation
Preliminary safety evaluation

7. Gantt chart

9. Chemical and process development phase and process engineering phase
Dynamic reactor model generation and calculation
Dynamic separation model generation and calculation
Scale up of process and equipment
Control design
Dynamic utility calculation
Dynamic waste and emission calculation

10. Commissioning and start up phase
Operator training
Troubleshooting
Model validation
Optimization
Process improvements

11. Chemical and process engineering

12. Process models Kinetic models Reactor models Liquid phase Gas phase
Interfacial fluxes
Solid-liquid reaction
Catalytic reaction

13. Scale up issue Similarity principle says that
“For any two dynamically similar systems, all the dimensionless numbers necessary to describe the process have the same numerical value”.

14. Similarity
Geometrical
Kinematic
Dynamic

15. Scale up procedure
Describe the process using a complete set of dimensionless numbers
Match these numbers at different scales

16. Dimensional analysis
Dimensional analysis is a method for producing dimensionless numbers that completely describe the process. The analysis should be carried out before the measurements have been made, because dimensionless numbers essentially condense the frame in which the measurements are performed and evaluated. It can be applied even when the equations governing the process are not known.

17. Dimensional analysis Newton (Np) Froude (Fr) Reynolds (Re)
P - power consumption [ML2T-5]
ρ - specific density of particles [M L-5]
n - impeller speed [T-1]
d - impeller diameter [L]
g - gravitational constant [LT-2]
η - dynamic viscosity [M L-1 T-1]

18. Résumé
Dimensional Analysis provides a powerful scientific technique for scale up
This technique is proven by a century of engineering applications
Rational scale-up should replace empirical approach

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