Styrene Monomer Storage Abnormal Conditions

As mentioned in week 1 it is vital to know the temperature throughout the tank and therefore carefully thought out temperature monitoring would be critical in the design phase. Keep in mind if the tank is insulated then external temperature checking won’t be feasible. This could alert to abnormal conditions within the tank.

It is mentioned in supporting documentation that the density of the styrene mixture can change if polymerisation is occurring. Therefore, consideration should be given to the pumping arrangements. What will happen under this upset condition? Obviously, the last thing you want is an external leak of styrene monomer so perhaps the type of seal or some preventative measures like inlet strainer with high differential pressure alarm or an alarm on a pump parameter which could alert to a change in density.

Mentioned in the guidance is the potential that one could use inert gas or air to cool an out of control reaction before it becomes runaway. Making sure the facilities are there to do this safely will be critical to the success.

The tank requires regular cleaning. Ensure that the drainage of the tank is considered, this is a toxic substance we are dealing with no pockets. Ensure that access ways are considered, and appropriate facilities are available for venting the tank and checking the atmosphere, and any required PPE is available close to the worksite.

Don’t forget gas detection to determine if the worst happens. This should be arranged such that it can warn you before any styrene gas monomer impacts a population.

Finally when designing the overpressure protection remember that polymerisation generating gas is a real threat and overpressure protection should be designed to cope with this. Routing of the fluid discharged from overpressure protection or from the routine vent should be considered to reduce the potential to impact large populations.

Storage of the inhibitor is important to make sure you have it when you need it.