1. Chemical Engineering Plant Design
Lek Wantha
Lecture 03
The Nature of Process Synthesis and Analysis

2. Creative Aspects of Process Design
In many particular company, we might try to generate new ideal
To produce a purchased raw material
To convert a waste by-product to a valuable product
To create a new material
To find a new way of producing an existing product
To exploit a new technology

3. Creative Aspects of Process Design
Success Rates
Synthesis and analysis
Engineering Method
Level of engineering designs

4. Levels of Engineering Designs

5. A Hierarchical Approach to Conceptual Design
The engineering method indicates that we should solve design problems by first developing very simple solutions and then adding successive layers of details

6. A Hierarchical Approach to Conceptual Design
Example: Hydrodealkylation of Toluene (HDA process)
Toluene + H Benzene + CH4
2Benzene Diphenyl + H2

7. Example: Hydrodealkylation of Toluene (HDA process)

8. Example: Hydrodealkylation of Toluene (HDA process) – Energy Integration

9. Example: Hydrodealkylation of Toluene (HDA process) – Distillation Train

10. Example: Hydrodealkylation of Toluene (HDA process) – Distillation Train

11. Example: Hydrodealkylation of Toluene (HDA process) – Vapor Recovery System
As a vapor recovery system we could use one of these:
Condensation (high pressure, or low temperature, or both)
Absorption
Adsorption
A membrane process

12. Example: Hydrodealkylation of Toluene (HDA process) – Simplified Flowsheet

13. Example: Hydrodealkylation of Toluene (HDA process) – Recycle Structure

14. Example: Hydrodealkylation of Toluene (HDA process) – Input-Output Structure

15. Example: Hydrodealkylation of Toluene (HDA process) – Hierarchy of Decisions
Batch versus continuous
Input-output structure of the flowsheet
Recycle structure of the flowsheet
General structure of the separation system
Heat exchanger network