This document discusses different types of process diagrams used in chemical engineering, starting with the most basic and moving to more complex diagrams. It focuses on block flow diagrams (BFDs), explaining that BFDs break a process into basic elements like reactions and separations. BFDs provide an overall picture of a chemical process and are useful for orienting oneself and screening process alternatives. The document outlines conventions for BFDs, such as representing operations with blocks and showing major flows with arrows going left to right when possible. BFDs form the starting point for more detailed piping and instrumentation diagrams.

1. 1
Chapter 1
Lecture # 1-3
• Process Diagrams
• Block Flow Diagrams (BFD)

2. 2
Chemical Process Diagrams
THE MOST EFFECTIVE WAY OF COMMUNICATING
THE MOST EFFECTIVE WAY OF COMMUNICATING
INFORMATION ABOUT A PROCESS IS THROUGH
INFORMATION ABOUT A PROCESS IS THROUGH
THE USE OF
THE USE OF FLOW DIAGRAMS
FLOW DIAGRAMS

3. 3
Input-Output Diagram
A crude block flow diagram in which
only feed and product streams are
identified.

4. 4
Block Flow Diagram
Break the process into its basic elements
such as reaction, separation, and recycle
sections.

5. 5
Generic Diagram

6. 6
Generic Block Diagram
– Each of these blocks may contain several unit
operations. For example, A separation section might
contain (four distillation columns, two flash units,
and a liquid-liquid decanter)
– Reactor Feed preparation and Separator Feed
Preparation sections mainly involve changing the
conditions (temperature and pressure) of the process
streams to the conditions required by the reactor or
separator.

7. 7
Block Flow Diagram
(BFD)
include the material balance calculations.

8. 8
Process Flow Diagram
(PFD)
complete mass and energy balance and
preliminary equipment specifications.

9. 9
Piping and Instrumentation Diagram
(P&ID)
includes the mechanical and instrumentation
details.

10. 10
Level of Process Diagrams
Input/output diagram
BFD
Generic diagram
PFD
P&ID

11. 11
BFD
BFD
PFD
PFD
P&ID
P&ID
Level of
Complexity
Increases
Level of
Conceptual
Understanding
Increases
Level of Process Diagrams

12. 12
Block Flow Diagram
(BFD)
–
– Shows overall processing picture of a
Shows overall processing picture of a
chemical complex .
chemical complex .
–
– Useful as an orientation tool.
Useful as an orientation tool.
–
– Used to sketch out and screen potential
Used to sketch out and screen potential
process alternatives.
process alternatives.

13. 13
Block Flow Diagram
(BFD)
•
• Block Flow Process Diagram (BFPD)
Block Flow Process Diagram (BFPD)
–
– BFPD forms the starting point for developing PFD
BFPD forms the starting point for developing PFD
–
– BFPD is helpful in conceptualizing new processes
BFPD is helpful in conceptualizing new processes
–
– See Fig 1.1
See Fig 1.1
•
• Block Flow Plant Diagram
Block Flow Plant Diagram
–
– Gives a general view of a large complex plant
Gives a general view of a large complex plant
–
– See Fig 1.2
See Fig 1.2

14. 14
Block Flow Process Diagram

15. 15
Block Flow Plant Diagram

16. 16
Conventions and Formats
Conventions and Formats for BFD
1) Operations shown by blocks
2) Major flow lines shown with arrows
3) Flow goes from left to right whenever possible
4) Light streams toward top with heavy stream toward bottom
5) Critical information unique to process supplied
6) If lines cross, then horizontal line is continuous
7) Simplified material balance provided

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