Question

Consider the reactor system shown below. The reaction is exothermic so a cooling system is provided to remove the excess energy of the reaction. In the event that the cooling function is lost, the temperature of the reactor would increase. This would lead to an increase in reaction rate, leading to an additional energy release. The result would be a runaway reaction with pressures exceeding the bursting pressure level of the reactor vessel. The temperature within the reactor is measured and is used to control the cooling water flow rate by a valve. Perform a HAZOP study on this unit to improve the safety of the process. Use as a study node the cooling coil (process parameters: flow and temperature) and the stirrer (process parameters: agitation)

Answer 1

Hazop

Given system

exothermic reaction in reactor cooling is provided to remove excess energy

possible hazard is well described in problem statement

as we are asked to do Hazop study we need to follow guidelines of HAZOP

we need to follow this sequence for Hazop

• What is cause of accident Or what are the conditions that have potential of hazard
• what is Or will be the consequences of accident?
• what all we can to prevent those thing to first place?
• what other accidents can happen in system ?
• To make sure that solution for problem one will not cause another problem in system.
• can we be prepared before accident occur?

after doing HAZOP on this system we will get to know all about unit improvement & safety of the Process.

We can install alarm systems with controller If any reakdown occur in controller we will get notify before any hazard.

We need make sure about proper agitation as it directly affects the rate of heat transfer

In this process we have many parameters like

flow rate of feed ,temp of feed , rate of agitation

In cooling rate of coolent & temp of coolant .

we use controller for flowrate of coolent as per temp in system we can also install one more controller if temperature rises certain limit feed walve can be closed automatically or if alarmed it can be done manually.