HAZOP analysis is a set of formal hazard identification and elimination procedure designed to identify hazards to people, process plants and environment in a chemical process facility. It uses a systematic process to identify all possible deviations from normal operations and to ensure that appropriate safeguards are in place to help for preventing accidents. It is essentially a qualitative process.
6.3.2.1 Objectives of HAZOP
HAZOP is carried out to ensure the overall safety of the reactor and to prevent the errors or problems that could occur as show at the previous part. HAZOP is done:
a. To examine the inadequacies of the reactor by considering it as a fully integrated dynamic unit, rather than the ‘ad hoc’ design approach.
b. To coordinate the various discipline involved in the design of the reactor and provide a mean for systematic analysis of the reactor system.
c. To identify hazards or deficiency and operability problem that may occur in the reactor, which may lead to hazard such as fire, explosion, toxic release or reduce productivity.
d. To prevent hazards in process plants that is growing in complexity with standards that are no longer adequate.
6.3.2.2 HAZOP Procedures
The HAZOP is done by systematically examine the reactor design and asking questions using guide words representing deviations from the intended parameters of the process. A Process and Instrumentation Diagram (PID) is developed by referring to the HAZOP analysis which is shown in Figure 3.1.
Chapter 6: Packed Bed Reactor 1 Acrylic Acid Project
Table 6.26: HAZOP Analysis on Packed Bed Reactor 1 – Streamline 5
HAZARD AND OPERABILITY STUDY ACTION REPORT Prepared by: Jackson Toh
Equipment: Acrolein Packed Bed Reactor Line No: 5
Intention: Transfer of Glycerol feed at 275oC and 1.4 bar into the reactor Type of
Deviation
Guide Word
Possible Causes Consequences Actions
Flow No (A)
1.1 Major piping leakage and poor pipe connection
1.2 Piping blockage due to impurities
1.3 Feed (FIC 1) controller failure
1.4 Blockage of valve (V-102)
(B)
2.1 No flow of feed into the reactor 2.2 No reaction occur in the reactor 2.3 High pressure in pipeline
(C)
3.1 Regularly inspection and maintenance for FIC1 and V-102 3.2 Check for piping connection 3.3 Install analyzers to detect leakage
3.4 Install no flow alarm
3.5 Install pressure safety valve (PRV)
Less (D)
1.1 Partial piping blockage 1.2 Minor pipe leakage
(E)
2.1 Less flow of feed into the reactor
2.2 Reactor under filling
2.3 Runaway reaction may occur 2.4 Product yield decrease
(F)
3.1 As for (C): 3.1 – 3.3 3.2 Install low flow alarm
More (G)
1.1 Shutdown system failure 1.2 Operator error
- Incorrect specification and amount of process fluid charge
(H)
2.1 Reactor overfilling 2.2 Pipeline overpressure
2.3 High temperature in the reactor 2.4 As (E): 2.3 – 2.4
2.5 Rupture in the reactor 2.6 Potential fire and explosion hazard
(I)
3.1 Install flow indicator and controller (FIC1)
3.2 Install control valve (V-102) 3.4 Prepare a checklist for operator
Temperature Less (J) (K) (L)
Chapter 6: Packed Bed Reactor 1 Acrylic Acid Project
1.1 Heat loss
1.2 Temperature indicator (TIC1) is failure
1.3 Changes in ambient temperature
1.4 Input flow rate is too low 1.5 Heating system failure in the reactor
2.1 Decrease in reaction temperature 2.2 Incomplete reaction in the reactor
2.3 Decrease product yield 2.4 Phase change of substances 2.5 Poor heating effect in the reactor
3.1 Install low temperature alarm (TAH & TAL)
3.2 Install temperature indicator (TIC1)
More (M)
1.1 High ambient temperature 1.2 Input flow rate is too high 1.3 External heat source 1.4 More heating medium inflow
1.5 Increase in pressure 1.6 Higher heat transfer in the reactor
(N)
2.1 Increase in reaction temperature 2.3 As for (H): 2.3 – 2.6
(O)
3.1 Isolation from external heat and ignition source
3.2 Install temperature indicator (TIC1)
3.3 Install high temperature alarm (TAH)
3.4 Regularly maintenance of the reactor
Pressure Less (P)
1.1 Pressure indicator (PIC1) failure
1.2 External cooling 1.3 Undetectable leakage
(Q)
2.1 Poor heat transfer in the reactor 2.2 As for (E): 2.1 – 2.4
(R)
3.1 Install low pressure alarm (PAL)
3.2 Install pressure indicator (PIC1)
3.3 As for (C): 3.1 – 3.3 More (S)
1.1 Under cooling in the reactor
1.2 Imbalance of input and output
1.3 Exposure to heat source 1.4 Thermal shock
(T)
2.1 Pipe surging
2.2 As for (H): 2.1 – 2.6
(U)
3.1 Install high pressure alarm (PAH)
3.2 Install pressure gauge
3.3 Install fire alarm and explosion relief (FER)
3.4 As for (O): 3.1 3.5 As for (I): 3.4 Contamination High (V)
1.1 Feed source contaminated (W)
2.1 Possible poisoning the catalyst
(X)
3.1 As for (O): 3.3 – 3.4
Chapter 6: Packed Bed Reactor 1 Acrylic Acid Project
2.2 Unexpected reaction
2.3 As for (H): 2.3 – 2.6
Table 6.27: HAZOP Analysis on Packed Bed Reactor 1 – Streamline 6
HAZARD AND OPERABILITY STUDY ACTION REPORT Prepared by: Jackson Toh
Equipment: Acrolein Packed Bed Reactor Line No: 6
Intention: Transfer of acrolein product out from the reactor Type of
Deviation
Guide Word
Possible Causes Consequences Actions
Flow No 1.1 As for (A): 1.1 – 1.2 1.2 Equipment and flange failure
1.3 No flow to reactor
2.1 Pipeline under pressure 2.2 No feed to collecting column 2.3 As for (H): 2.3 – 2.6
3.1 Install flow indicator (FI1) 3.2 As for C: 3.1 – 3.5
Less 1.1 As for (D): 1.1 – 1.3 2.1 Collecting column under filling 2.2 Pipeline under pressure
2.3 As for (H): 2.3 – 2.6
3.1 As for (F): 3.1 – 3.3
More 1.2 As for (G): 1.2 – 1.3 2.1 Collecting column may rupture 2.2 Pipeline overpressure
2.3 Vapor cloud explosion may occur
3.1 As for (I): 3.1 – 3.4
Temperature Less 1.1 As for (J): 1.2 – 1.3 1.2 Heating system failure in the reactor
- poor heat transfer - heating medium failure
2.1 Change condition in collecting column
2.2 Phase change of substances 2.3 Poor heating effect in the reactor
3.1 As for (L): 3.1 – 3.2
3.2 Provide accurate temperature monitoring in the reactor
3.3 Ensure the heating system function well
More 1.1 As for (M): 1.1 – 1.3 1.2 Heating system failure in the reactor
- overheating from the molten salt
2.1 Over heating effect in the reactor 2.2 Fouling
2.3 Injuries and fatalities 2.4 As for (H): 2.3 – 2.6
3.1 As for (O): 3.1 – 3.3
3.2 Regularly maintenance of the reactor heating system
Pressure Less 1.1 As for (P): 1.1 – 1.3 1.2 Generation of vacuum
2.1 Under filling in collecting column 2.2 Additional pump is needed to
3.1 As for (L): 3.1 – 3.2
Chapter 6: Packed Bed Reactor 1 Acrylic Acid Project condition increase the pressure of product to
collecting column More 1.1 Uncontrolled reaction in
reactor
1.2 Pressure relief valve (PRV) failure
1.3 overfilling in the reactor 1.4 As for (S): 1.2 – 1.4
2.1 Pipe surging
2.2 Overfilling in collecting column 2.3 Overpressure in collecting system 2.2 As for (H): 2.3 – 2.6
3.1 As for (U): 3.1 – 3.4
3.2 Install pressure indicator (PI1)
Table 6.28: HAZOP Analysis on Packed Bed Reactor 1 – Streamline H_1
HAZARD AND OPERABILITY STUDY ACTION REPORT Prepared by: Jackson Toh
Equipment: Acrolein Packed Bed Reactor Line No: H_1
Intention: Transfer of hot molten salt into the reactor Type of
Deviation
Guide Word
Possible Causes Consequences Actions
Flow No 1.1 As for (A): 1.1 – 1.3 1.2 Equipment and flange failure
2.1 No hot molten salt flow into the reactor
2.2 No heat transfer takes place 2.3 As for (K): 2.1-2.5
3.1 As for (L): 3.1 – 3.2
Less 1.1 As for (D): 1.1 – 1.3 1.2 Fouling in the reactor
2.1 As for (K): 2.1-2.5 3.1 As for (F): 3.1 – 3.3
More 1.1 As for (G): 1.1 – 1.2 2.1 Improper heating in the reactor