Hazop

1. Reactor
Table 6 Reactor HAZOP Sheet
HAZOP STUDY RECORD
SHEET
PROJECT: TEREPHTHALIC ACID
MAJOR UNIT: REACTOR
Stream
System : TPA Production Study node: Inlet to Reactor
(Air + Acetic Acid + p-
Xylene)
Deviation
Parameter
Guide Word
Possible
consequences
Possible causes
Safeguard/ Action
required
Flow
More
1. Upsetting
process
2. Uncontrolled
reaction
3. Excessive heat
• Excess air
• Excess Air Valve
fully open
• Install high flow alarm
• Install dry air control
valve after compressor.
• Operator to
continuously monitor
pipe/valve condition
and manually change
valve position
no
• No reaction
• No product
• Pipe rupture
• Valve fully
closed
• Blockage
• Install feed flow meter
• To be included in
biweekly routine
checkup procedure by
Inspection Team
Less
• Less pressure
• Less favorable
product
• Pipe leakage
• Valve partially
closed
• Install low flow alarm
• Operator to
continuously monitor
pipe/valve condition
and manually change
valve position
Pressure
More
• High velocity
of reactant
• Overpressure
• High
temperature
• Valve failure
• Overheat
• High pressure alarm
• Install pressure safety
valve (PSV)
• Install high
temperature alarm
Less
• Less reaction
• Less favorable
product
• Leakage
• Compressor
failure
• Insert safety valve
• Install low pressure
alarm
Temperature
More
• Uncontrolled
reaction
• Mechanical
failure
• May cause
explosion
• Pressure increase
 Install temperature
sensor

2. Crystallizer
Table 7 Crystallizer HAZOP Sheet
Less
• Less pressure,
less favorable
product.
• Low pressure
• Install temperature
sensor
HAZOP STUDY
RECORD SHEET
PROJECT: TEREPHTHALIC ACID
MAJOR UNIT : CRYSTALLIZER
Stream
System : TPA
Production
Study node: Outlet of Reactor TPA mixture
Guide
Word
Deviation
Possible
Consequences
Possible Causes
Safeguard/Action
required
Flow
More
• Upsetting
process
• Increase
demand for
solvent
• Increase in
temperature
• Uncontrolled
reaction
• Install high flow alarm
• Regular monitoring by Control Team.
No  No product
• Pipe rupture,
valve fully
closed, blockage
• No reaction
• To be included in biweekly routine
checkup procedure by Inspection Team
• Regular monitoring by Control Team
• Operator to continuously monitor
pipe/valve condition and manually change
valve position
Less
• Less product
form
• Decrease in
temperature
• Low reaction rate
• Pipe leakage
• Valve partially
closed
• Install low flow alarm
• To be included in biweekly routine
checkup procedure by Inspection Team
• Regular monitoring by Control Team

3. Scrubber
Table 8 Scrubber HAZOP Sheet
Dryer
Table 9 Dryer HAZOP Sheet
Item Guide word Deviation Possible consequences Possible causes
Safeguard/ Action
required
S
C
R
U
B
B
E
R
Pressure
More
 Low absorption
rate
 Uncontrolled
reaction
 Install pressure safety
valve (PSV)
 Install high pressure
alarm
Less
 Less flow rate to
the absorber
 Agitate absorption
process
 Take longer time
 Low reaction
rate
 Pipe leakage
 Install low flow alarm
 Operator to monitor
pipe/valve condition
 Regular monitoring by
Control Team
Temperature
More
 Increase in utility
 Uncontrolled
process
conditions
 Install temperature
sensor
 Install auto-control
valve for utility
less
 Less pressure
 Take longer time
for absorption
process
 Low absorption
rate
 Install temperature
sensor
Item Guide Word Deviation Possible Consequences Possible Causes Safeguard/ Action required
D
R
Y
E
R
Pressure
More  Low drying rate
 Uncontrolled air
flowrate
 Install pressure safety
valve (PSV)
 Install high pressure
alarm
Less
 Less flow rate to the
dryer
 Improve steam
flowrate to the
process
 Take longer time
 Low drying rate
 Pipe leakage
 Install low flow alarm
 Operator to monitor
pipe/valve condition
 Regular monitoring by
Control Team
More
 Increase in utility  Uncontrolled
drying process
 Install temperature
sensor

4. Temperature
 Install auto-control
valve for utility
less
 Less pressure
 Longer time for
drying process
 Low flowrate
 Install temperature
sensor