HAZOP Case Studies for Workshop Session

HAZOP Case Studies – Example 1 Cooling Coils Monomer Feed

Refer to reactor system shown.

Cooling Water to Sewer

The reaction is exothermic. A cooling system is provided to remove the excess energy of reaction. In the event of cooling function is lost, the temperature of reactor would increase. This would lead to an increase in reaction rate leading to additional energy release.

Cooling Water In

T C

Thermocouple

The result could be a runaway reaction with pressures exceeding the bursting pressure of the reactor. The temperature within the reactor is measured and is used to control the cooling water flow rate by a valve. Perform HAZOP Study

1

Process Risk Seminar 22nd Dec 2009 Workshop Session

Preliminary HAZOP on Reactor – Example – fill in the gaps Guide Word

Deviation

Causes

Consequences

Action

NO

No cooling

REVERSE

Reverse cooling flow

MORE

More cooling flow

Instruct operators on procedures

AS WELL AS

Reactor product in coils

Check maintenance procedures and schedules

OTHER THAN

Another material besides cooling water

Temperature increase in reactor Failure of water source resulting in backward flow

Water source contaminated

Process Risk Seminar 22nd Dec 2009 Workshop Session

2

Case Study – Shell & Tube Heat Exchanger Using relevant guide works, perform HAZOP study on shell & tube heat exchanger

Process fluid

Cooling water

3

Process Risk Seminar 22nd Dec 2009 Workshop Session

HAZOP Study Form HAZOP STUDY REPORT FORM TITLE :

Sheet 1 of LINE 1 : CAUSES

CONSEQUENCES

DEVIATION

4

Process Risk Seminar 22nd Dec 2009 Workshop Session

ACTIONS, QUESTIONS OR RECOMMENDATIONS